Quartz
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About Quartz
Formula:
SiO2
Colour:
Colorless, purple, rose, red, black, yellow, brown, green, blue, orange, etc.
Lustre:
Vitreous
Hardness:
7
Specific Gravity:
2.65 - 2.66
Crystal System:
Trigonal
Name:
Quartz has been known and appreciated since pre-historic times. The most ancient name known is recorded by Theophrastus in about 300-325 BCE, κρύσταλλος or kristallos. The varietal names, rock crystal and bergcrystal, preserve the ancient usage. The root words κρύοσ signifying ice cold and στέλλειυ to contract (or solidify) suggest the ancient belief that kristallos was permanently solidified ice.
The earliest printed use of "querz" was anonymously published in 1505, but attributed to a physician in Freiberg, Germany, Ulrich Rülein von Kalbe (a.k.a. Rülein von Calw, 1527). Agricola used the spelling "quarzum" (Agricola 1530) as well as "querze", but Agricola also referred to "crystallum", "silicum", "silex", and silice". Tomkeieff (1941) suggested an etymology for quartz: "The Saxon miners called large veins - Gänge, and the small cross veins or stringers - Querklüfte. The name ore (Erz, Ertz) was applied to the metallic minerals, the gangue or to the vein material as a whole. In the Erzgebirge, silver ore is frequently found in small cross veins composed of silica. It may be that this ore was called by the Saxon miners 'Querkluftertz' or the cross-vein-ore. Such a clumsy word as 'Querkluftertz' could easily be condensed to 'Querertz' and then to 'Quertz', and eventually become 'Quarz' in German, 'quarzum' in Latin and 'quartz' in English." Tomkeieff (1941, q.v.) noted that "quarz", in its various spellings, was not used by other noted contemporary authors. "Quarz" was used in later literature referring to the Saxony mining district, but seldom elsewhere.
Gradually, there were more references to quartz: E. Brown in 1685 and Johan Gottschalk Wallerius in 1747. In 1669, Nicolaus Steno (Niels Steensen) obliquely formulated the concept of the constancy of interfacial angles in the caption of an illustration of quartz crystals. He referred to them as "cristallus" and "crystallus montium".
Tomkeieff (1941) also noted that Erasmus Bartholinus (1669) used the various spellings for "crystal" to signify other species than quartz and that crystal could refer to other "angulata corpora" (bodies with angles): "In any case in the second half of the XVIIIth century quartz became established as a name of a particular mineral and the name crystal became a generic term synonymous with the old term 'corpus angulatum'."
The earliest printed use of "querz" was anonymously published in 1505, but attributed to a physician in Freiberg, Germany, Ulrich Rülein von Kalbe (a.k.a. Rülein von Calw, 1527). Agricola used the spelling "quarzum" (Agricola 1530) as well as "querze", but Agricola also referred to "crystallum", "silicum", "silex", and silice". Tomkeieff (1941) suggested an etymology for quartz: "The Saxon miners called large veins - Gänge, and the small cross veins or stringers - Querklüfte. The name ore (Erz, Ertz) was applied to the metallic minerals, the gangue or to the vein material as a whole. In the Erzgebirge, silver ore is frequently found in small cross veins composed of silica. It may be that this ore was called by the Saxon miners 'Querkluftertz' or the cross-vein-ore. Such a clumsy word as 'Querkluftertz' could easily be condensed to 'Querertz' and then to 'Quertz', and eventually become 'Quarz' in German, 'quarzum' in Latin and 'quartz' in English." Tomkeieff (1941, q.v.) noted that "quarz", in its various spellings, was not used by other noted contemporary authors. "Quarz" was used in later literature referring to the Saxony mining district, but seldom elsewhere.
Gradually, there were more references to quartz: E. Brown in 1685 and Johan Gottschalk Wallerius in 1747. In 1669, Nicolaus Steno (Niels Steensen) obliquely formulated the concept of the constancy of interfacial angles in the caption of an illustration of quartz crystals. He referred to them as "cristallus" and "crystallus montium".
Tomkeieff (1941) also noted that Erasmus Bartholinus (1669) used the various spellings for "crystal" to signify other species than quartz and that crystal could refer to other "angulata corpora" (bodies with angles): "In any case in the second half of the XVIIIth century quartz became established as a name of a particular mineral and the name crystal became a generic term synonymous with the old term 'corpus angulatum'."
Polymorph of:
Isostructural with:
Quartz is one of the most common minerals found in the Earth's crust. If pure, quartz forms colorless, transparent and very hard crystals with a glass-like luster. A significant component of many igneous, metamorphic and sedimentary rocks, this natural form of silicon dioxide is found in an impressive range of varieties and colours.
The Si analogue of pertoldite.
Quartz occurs in two basic forms:
1. The more common macrocrystalline quartz is made of visible crystals or grains. Examples are rock crystals, the grains in sandstone, but also massive quartz that is made of large crystallites without any crystal faces, like vein quartz.
2. Cryptocrystalline quartz or microcrystalline quartz is made of dense and compact aggregates of microscopic quartz crystals and crystallites. Examples are agate and chert. The different types of cryptocrystalline quartz are colloquially subsumed under the term chalcedony, although that term has a more strict definition in scientific literature. It is worth mentioning that most chalcedony contains small amounts of another SiO2 polymorph, moganite, so it is not always pure quartz.
Quartz crystals or aggregates that share certain peculiar physical properties have been classified as quartz varieties with specific "trivial names".
The best known examples are the colored varieties of quartz, like amethyst or smoky quartz, but there are also trivial names for specific crystal shapes, aggregates and textures, like scepter quartz, gwindel or quartzine. Because there are no canonical rules on naming or defining quartz varieties like they are for minerals, the definitions of some quartz varieties are precise and generally accepted, while the definitions of others vary considerably between different authors, or are rather fuzzy.
Mindat Classification of Quartz Varieties
On Mindat, macrocrystalline quartz and its varieties are listed as quartz and varieties of quartz.
Cryptocrystalline quartz and its varieties are listed as chalcedony, like "Quartz (Var: Chalcedony)", or as variety of chalcedony, like "Chalcedony (Var: Agate)".
More about the specific properties of chalcedony and its varieties can be found at the respective mineral pages.
Note that, contrary to minerals, the definitions of varieties are not mutually exclusive in the sense that no mineral can be another. A single specimen can be correctly classified as several varieties.
Quartz can be thought of as being made of threefold and sixfold helical chains of SiO4 tetrahedra that run parallel to the c axis. Figure 1 shows two representations of a threefold SiO4 helix and its relationship to the quartz unit cell: to the right a ball model with red oxygen and white silicon atoms, to the left a tetrahedral model, with the corners of the tetrahedra at the position of the oxygen atoms.
Six of such helices are connected to form a ring that surrounds a central channel which runs parallel to the c-axis, sometimes called "c-channel". The SiO4 tetrahedra around the central c-channel form two independent sixfold helices. Figure 2 shows two views of the corresponding structure: looking in the direction of the c-axis in the top row, and looking in the direction of an a-axis in the bottom row. Like quartz crystals, the ring is six-sided but has a trigonal symmetry. The large channels are an important structural feature of quartz because they may be occupied by small cations.
You can explore the crystal structure of quartz with the interactive tool JSmol further down this page.
A helix is either turning clockwise (right-handed) or counter-clockwise (left-handed). Due to the helical arrangement of the SiO4 tetrahedra, the atomic lattice of quartz possesses the symmetry properties of a helix: Quartz forms left- and right-handed crystals, whose crystal structure and morphology are mirror-images of each other.
In a crystal with space group P3121 (right), the sixfold helices turn counter-clockwise (left) and the threefold helices clockwise (right).
In a crystal with space group P3221 (left), the sixfold helices turn clockwise (right) and the threefold helices counter-clockwise (left).
For a thorough review of the symmetry features of quartz, see Heaney (1994).
The crystallographic form of quartz that is characteristic for its symmetry properties is the trigonal trapezohedron. The position of the faces of the positive trigonal trapezohedra on the crystal reflects the handedness of the structure of the crystal. The figure to the right visualizes the relationship between the handedness of the six-fold helices and the position of the faces of the positive trigonal trapezohedron (x - orange) and the trigonal bipyramid (s - blue). Unfortunately, these faces are not present on all crystals, and often it is not possible to determine the handedness of a crystal from its morphology.
Quartz is optically active: the polarization of a light ray passing through a crystal parallel to the c-axis will be rotated either to the left or the right, depending on the handedness of the crystal (Arago, 1811; Biot, 1812; Herschel, 1822). The relationship between handedness of the crystals and the symmetry of the structure and hence the optical rotation was determined by de Vries (1958).
The following table lists how symmetry, morphology and optical behaviour are related.
Note that the morphological handedness as expressed by the position of the trapezohedral and bipyramidal faces x and s does not match the symmetry's handedness:
Quartz is found as individual crystals and as crystal aggregates. Well crystallized quartz crystals are typically six-sided prisms with steep pyramidal terminations. They can be stubby ("short prismatic") or elongated and even needle-like. In most environments quartz crystals are attached to the host rock and only have one tip, but double-terminated crystals are also found.
As a rock-forming mineral, quartz commonly occurs as sub-millimeter to centimeter-sized anhedral grains, well-formed crystals are uncommon. Secondary vein-fillings of quartz are typically massive.
Quartz belongs to the trigonal-trapezohedral crystal class 32. Of the seven basic crystallographic forms of this crystal class, the hexagonal prism and trigonal rhombohedra are very common and determine the overall shape of the crystals. The trigonal bipyramids and trigonal trapezohedra are frequently found, but typically only as relatively small faces. The trigonal prisms, the basal pinacoid and in particular ditrigonal prisms are very rare (Frondel, 1962).
Quartz crystals show about 100 different crystallographic forms in nature (Frondel, 1962; Rykart, 1995). It is convenient and common practice to designate them with Latin and Greek letter symbols instead of Miller-Bravais indices. The following figure illustrates the relation of the common forms (sorted by abundance) to the faces found on quartz crystals. The most common combination of crystallographic forms in quartz crystals is r+m+z.
The handedness of quartz crystals can be determined easily from the positions of x faces, which are at the lower left or lower right corner of the r face (orange faces in Fig.5). With some difficulty the handedness can be determined from the position of the s faces (blue faces in Fig.5), which lie between the r and z faces: the s face often shows a fine striation that runs parallel to the edge of the r-face.
The bottom row shows a top view of the crystals. It does not only show their trigonal symmetry but also the chirality of the position of the x faces.
Macroscopic Structure of Quartz Crystals
In response to lattice defects, and apparently reflecting their growth conditions, quartz crystals may develop two very distinct and mutually exclusive types of internal structure:
- Macromosaic Structure, sometimes called "Friedlaender Quartz"
- Lamellar Structure, sometimes called "Bambauer Quartz"
Individual crystals may possess both structural types, but the respective parts of the crystals grew at different developmental stages (Hertweck et al., 1998). It is sometimes claimed that all quartz occurs either as macromosaic or as lamellar structural type. This is not correct.
The lamellar structure was first described by Weil (1931). The crystals contain layers that show an optical anomaly: they are biaxial. The layers are stacked parallel to the crystal faces in an onion-like manner and were found to be associated with a relatively high hydrogen and aluminium content (Bambauer et al., 1961, 1962, 1963). Lamellar quartz cannot be safely recognized without studying the optical properties of the crystal in a thin section.
Macromosaic quartz crystals have been described by Friedlaender (1951) and are composed of slightly tilted and radially arranged wedge-shaped sectors. They are recognized by the presence of sutures on the crystal faces which are often confused with twin boundaries. Crystals with such a structure are found in pegmatite and miarole pockets and in high-temperature alpine-type fissures.
Quartz Crystal Habits
Strictly speaking, the term "habit" is used to designate the overall shape of individual crystals, regardless of the crystallographic forms (crystal faces) involved. Confusingly, the definitions of some habits of quartz crystals do include specific forms. Many of the trivial names of these habits have been introduced and popularized by rock hounds in the Alps (for a good overview, see Rykart, 1995). The most important habits with trivial names (with synonyms in different languages in braces) are:
a) Normal habit ("Maderaner Habitus", prismatic habit): "typical" quartz crystals that are not or only slightly tapered.
b) Trigonal habit: Crystals with obvious trigonal symmetry, for example, because of missing z faces, or because of a triangular cross section, like in crystals with a Muzo habit (h).
c) Pseudohexagonal habit: Crystals with an even development of rhombohedral and prism faces.
d) Cumberland habit: Crystals with very small or absent prism faces, often bipyramidal.
e) Pseudocubic quartz (pseudocubic habit, cubic habit, cube quartz, "Würfelquarz"): Crystals with a dominant r or z form that look like slightly distorted cubes.
f) Dauphiné habit: Crystal tips with a single very dominant rhombohedral face.
g) Tessin habit ("Abito Ticino", "Tessiner Habitus", "Rauriser Habitus", "Penninischer Habitus", "Acute Rhombohedral Habit"): Crystals that are tapered by steep rhombohedral faces { h 0 i 1 }, Tessin habit in the strict sense is dominated by { 4 0 4 1 } and { 3 0 3 1 } faces. At the original locality, they possess a macromosaic structure.
h) Muzo habit: Crystals with prism faces that are tapered under the z faces because these are made of a succession of alternating m and z faces, and who have a trigonal cross section at the crystal tips (Gansser, 1963).
Needle quartz (acicular habit): Crystals greatly elongated along the c-axis.
Quartz Growth Forms
In addition to crystallographic forms and habits, many quartz crystals are characterized by peculiar morphological features that reflect different modes of growth during their development. Some of these "growth forms" are found at many different localities and - like habits - have been given "trivial names" (e.g., "cactus quartz", "gwindel"). Some of these are listed as varieties of quartz on Mindat. Among the more common and important growth forms are:
Sceptre quartz: Crystals with syntaxial overgrowth of a second generation tip.
Faden quartz: Crystals and crystal aggregates with a white thread running through the crystals. The thread is caused by repetitive cracking of the crystal during growth and consists of fluid inclusions.
Window or Skeleton or Frame or Fenster quartz: Crystals with frame-like, elevated edges of the crystal faces, usually with parallel grown blades that grow from the edges to the center of the faces in a window glass-like manner. Hopper crystals that correspond to skeleton-growth in the strict sense are rare.
Phantom quartz: Crystals in which outlines of the shape of earlier developmental stages of the crystal are visible because of inclusions or color zones.
Sprouting quartz ("Sprossenquarz"): Crystals on which split-growth causes subparallel daughter crystals to sprout from the crystal faces
Artichoke quartz: A form of split-growth resulting in specimens with composite artichoke-like crystal tips.
Gwindel: Crystals elongated and twisted along an a-axis.
Cactus quartz or spirit quartz: Crystals whose prism faces are covered by small, roughly radially grown second-generation crystals.
Quartz Twins
Twinning is very common in quartz, but is often inconspicuous and difficult to recognize. Two types of twinning can be distinguished (data in tables from Jentzsch, 1867, 1868; Gault, 1949; Frondel, 1962):
1. Twins with parallel main crystallographic axes
Dauphiné and Brazil law twins are very common. Most crystals, even if morphologically untwinned, contain at least small twin domains. Both types of twins can be found in a single crystal.
Dauphiné Law
Also called: Swiss Law, Alpine Law
Dauphiné law twins can be thought of as a merger of two crystals of equal handedness that are rotated by 60° around the c-axis relative to each other (Weiss, 1816). They are penetration twins composed of twin domains with irregular boundaries (Leydolt, 1855). The size and shape of the twin domains can vary and the shares of the twin domains in a crystal do not have to be equal. The degree of intergrowth of the domains may increase during growth, starting from roughly triangular sectors at the base to complex irregular patterns at the tip of the crystal (Friedlaender, 1951). Twin domains are only rarely visible in natural crystals and normally need to get visualized by etching the surface or a polished cross-section (Leydolt, 1855; Judd, 1888). Electron microscopical studies reveal that on a small scale the twin domains look like complex polygons with straight boundaries (Lang, 1965; McLaren and Phakey, 1969).
Dauphiné twins can sometimes be recognised by the position and arrangement of crystal faces, in particular, the x-faces. Because the rhombohedral faces are composites of r and z faces, they do not show the common size difference of the faces and the crystals assume a pseudohexagonal habit.
Rarely Dauphiné twinned crystals that lack one type of rhombohedral face (either r or z) - and that would display a trigonal habit if they were untwinned - show re-entrant angles at the tip that make them look like drill heads (for example, Schäfer, 1999).
Dauphiné twins are sometimes called electrical twins, because this kind of twinning reduces or even suppresses the piezoelectricity that is typical for untwinned quartz crystals, while their optical activity remains unaffected (Thomas, 1945; Donnay and Le Page, 1975).
Brazil Law
Also called: Optical Law
Brazil law twins can be thought of as a merger of a left- and right-handed crystal: they are penetration twins composed of left- and right-handed domains. Their twin boundaries are usually straight lines, resulting in a characteristic pattern made of straight lines and triangles (Leydolt, 1855). As with Dauphiné twins, the twin domains are usually not visible in natural crystals and need to be visualized by etching (Leydolt, 1855). The corresponding surface patterns on crystal faces are polygonal patches with straight boundaries, often triangular.
Brazil law twins that show the ideal arrangement of x and s crystal faces are very rare.
Many amethysts are twinned polysynthetically according to the Brazil Law: Parts of the amethyst crystals, in particular in zones under the r rhombohedral faces are composed of alternating layers of left- and right-handed quartz (Brewster 1823; McLaren and Pitkethly, 1982; Taijing and Sunagawa, 1990). The gauge of individual layers is normally less than 1 mm. The layered structure may be visible as a fingerprint-like pattern on rhombohedral faces.
Brazil law twins are sometimes called optical twins, because this kind of twinning reduces or even suppresses the optical activity typical for quartz crystals. Confusingly, and contrary to common belief, Brazil law twinning does also reduce or suppress the piezoelectricity of quartz crystals (Thomas, 1945; Donnay and Le Page, 1975).
Combined Law
Also called: Liebisch Law, Dauphiné-Brazil Law, Leydolt Law
It is not unusual for crystals to show Dauphiné and Brazil law domains in one crystal, and sometimes crystals show x or s faces at positions that would indicate a special type of twinning. Electron microscopic studies show that when Brazil law twins are heated and develop new Dauphiné twin domains, their left- and right-handed domains do not share boundaries when they are rotated with respect to each other (Van Goethem et al., 1977), so Liebisch twinning seems to be energetically less favorable. Accordingly, Liebisch twinning is rare.
2. Twins with inclined main crystallographic axes (incomplete list)
Of the twins with inclined main axes, only the Japan law twin is common and well established, while for some of the others (including some that are not listed here) only a few and sometimes only one specimen have been reported and the existence of a twin law is questionable. The Reichenstein-Grieserntal Law is sometimes erroneously called "Esterel Law", which is the equivalent for beta-quartz.
Japan Law
Also called: Weiss Law, La Gardette Law
Japan law twins are the only common quartz twins with inclined c axes. The law was first found and described by Weiss (1829) on crystals from La Gardette, France, but the name "Japan law" became more popular after a great number of them were found in Japan. The c-axis of two crystals meet at an angle of 84°33', with two of the m prism faces of both crystals being parallel. The twinning plane {1 1 2 2} of Japan law twins corresponds to the flat trigonal bipyramid ξ (the Greek letter xi).
Japan law twins are contact twins (Sunagawa and Yasuda, 1983). The twin junctions often look jagged on the crystal surface, but are perfectly straight in the interior of the crystals, and form a thin plane that runs from the base of the crystal to the V-shaped indentation between the branches (Sunagawa and Yasuda, 1983). Electron microscopic studies revealed that the twin boundary also forms a perfect plane parallel to {1 1 2 2} (Lenart et al. 2012; Momma et al. 2015), but appears to be restricted to the initial growth periods of the crystal, extending only a few hundred micrometers, which has been interpreted as an indication of a formation as a nucleation twin (Lenart et al. 2012). The cause of the twin formation is still not understood.
Most Japan law twins are flattened, and often they are larger than untwinned crystals that accompany them. Depending on the handedness of the two branches of a twin, one can distinguish 8 different basic twinning subtypes that are also twinned according to the Brazil or Dauphiné law (Frondel, 1962), but the pattern of Brazil and Dauphiné twin domains can be very complex (Kozu, 1952).
Compared to many other minerals, quartz is chemically very pure, most crystals contain more than 99.5% SiO2. Nevertheless, varieties colored by impurities occur. These can be devided into two groups:
1. Quartz colored by trace elements built into the crystal lattice.
Only a few elements can replace silicon in the quartz lattice (substitutional positions) or are small enough to occupy free spaces in the lattice (interstitial positions). In natural quartz crystals, the most common ones to replace Si are Al, Fe, Ge, and Ti, whereas Li, Na, Ca, Mg and Fe often occupy interstitial positions in the "c-channels" mentioned under "Structure of Quartz". Of the substitutional trace elements, only Al, Fe and more rarely P are found to play a role in natural colored varieties. There are only a handful of quartz varieties colored by trace elements built into the lattice, sorted by abundance, with the more common ones first:
- Smoky quartz
- Amethyst
- Citrine
- Pink Quartz / Euhedral Rose Quartz
- Prasiolite
With the possible exception of some prasiolites and some citrines, the color of these varieties is based on color centers whose formation requires high energy irradiation from radioactive elements in the surrounding rocks (O'Brien, 1955; Lehmann and Moore, 1966; Maschmeyer et al., 1980; Maschmeier and Lehmann, 1983). Quartz varieties based on color centers are pleochroic, and their color centers can be destroyed by heat treatment.
Note that individual quartz crystals may contain several colored varieties, like an amethyst with smoky zones.
2. Quartz colored by inclusions of separate phases, for example minerals or fluids.
Because quartz crystals grow in many geological environments, they embed many different minerals during growth and assume the colors of the included minerals. Colors may also be caused by light scattering at finely distributed but colorless inclusions.
There are also trivial names for varieties colored by inclusions that have been found at many localities, like "prase", "ferruginous quartz" or "rose quartz". However, the definitions of these varieties are often rather fuzzy, and different authors use different definitions.
Quartz is one of the crystalline forms of silica, the essential building material for all silicates, and quartz can only form where silica is present in excess of what is consumed in the formation of other silicate minerals.
Quartz may also be consumed during the formation of new silicate minerals, in particular at higher temperatures and pressures, and certain geological environments are "incompatible" with free silica and hence quartz.
Quartz as a Rock-Forming Mineral
Silica has been enriched in the continental Earth's crust to about 60% (Rudnick and Gao, 2003) by processes like magmatic differentiation and the formation of silica-rich igneous rocks (mainly driven by plate tectonics) and the accumulation of the physically and chemically stable quartz in sediments and sedimentary rocks. The oceanic crust's silica content of about 50% (White and Klein, 2014) in its igneous rocks is too low for quartz to form in them.
The largest amount of quartz is found as a rock-forming mineral in silica-rich igneous rocks, namely granite-like plutonic rocks, and in the metamorphic rocks that are derived from them. Under conditions at or near the surface, quartz is generally more stable than most other rock-forming minerals and its accumulation in sediments leads to rocks that are highly enriched in quartz, like sandstones. Quartz is also a major constituent of sedimentary rocks whose high quartz content is not immediately obvious, like slates, as well as in the metamorphic rocks derived from such quartz-bearing precursor rocks.
Quartz Veins
At higher temperatures and pressures quartz is easily dissolved by watery fluids percolating the rock. When silica-rich solutions penetrate cooler rocks, the silica will precipitate as quartz in fissures, forming thin white seams as well as large veins which may extend over many kilometers (Bons, 2001; Wangen and Munz, 2004, Pati et al, 2007). In most cases, the quartz in these veins will be massive, but they may also contain well-formed quartz crystals. Phyllites and schists often contain thin lenticular or regular veins of so-called "segregation quartz" (Vinx, 2013) that run parallel to the bedding and are the result of local transport of silica during metamorphosis (Chapman, 1950; Sawyer and Robin, 1986). Silica-rich fluids are also driven out of solidifying magma bodies. When these hot brines enter cooler rocks, the solution gets oversaturated in silica, and quartz forms.
Along with the silica, metals are also transported with the brines and precipitate in the veins as sometimes valuable ore minerals. The association of gold and quartz veins is a well-known example. Quartz is the most common "gangue mineral" in ore deposits.
Quartz Crystals
Quartz crystals typically grow in fluids at elevated temperatures between 150°C and 600°C, but they also grow at ambient conditions (Mackenzie and Gees, 1971; Ries and Menckhoff, 2008).
Quartz is best known for the beautiful crystals it forms in all sorts of cavities and fissures. The greatest variety of shapes and colors of quartz crystals comes from hydrothermal ore veins and deposits, reflecting large differences in growth conditions in these environments (chemistry, temperature, pressure). Splendid, large crystals grow from ascending hot brines in large fissures, from residual silica-rich fluids in cavities in pegmatites and from locally mobilized silica in Alpine-type fissures. An economically important source of amethyst for the lapidary industry are cavities of volcanic rocks. Small, but well-formed quartz crystals are found in septarian nodules, and in dissolution pockets in limestones.
Well-formed quartz crystals that are fully embedded in sedimentary rocks and grew during diagenesis (so-called authigenic quartz crystals) are occasionally found in limestones, marls, and evaporites (e.g. Rykart, 1984).
Euhedral quartz crystals that are embedded in igneous rocks are uncommon. Quartz is among the last minerals that form during the solidification of a magma, and because the crystals fill the residual space between the older crystals of other minerals they are usually irregular. Euhedral, stubby bipyramidal quartz crystals are occasionally found in rhyolites. These are usually paramorphs after beta-quartz with hexagonal symmetry, quartz crystals whose trigonal habit shows that they grew as alpha-quartz are very rare in volcanic rocks (e.g. Flick and Weissenbach, 1978). Only rarely are euhedral quartz crystals seen embedded in metamorphic rocks (Kenngott, 1854; Tschermak, 1874; Heddle, 1901).
In most cases quartz is easy to identify by its combination of the following properties:
- hardness (easily scratches glass, also harder than steel)
- glass-like luster
- poor to indistinct cleavage
- conchoidal fracture in crystals, in massive specimens the fracture often looks irregular to the naked eye, but still conchoidal at high magnification.
Note that in macrocrystalline quartz the fracture surfaces have a vitreous to resinous luster, whereas in cryptocrystalline quartz (chalcedony) fractured surfaces are dull.
Crystals are very common and their usually six-sided shape and six-sided pyramidal tips are well-known. Intergrown crystals without tips can often be recognized by the presence of the characteristic striation on the prism faces.
Quartz as a rock-forming mineral, in particular as irregular grains in the matrix, occasionally poses problems and may require additional means of identification. It may be confused with cordierite (pleochroic, tendency to alteration) and nepheline (lower hardness, geological environment incompatible with quartz).
In thin sections macrocrystalline quartz appears clear and homogeneous, with blue-gray to white or bright yellow interference colors and a low relief. Quartz does not show alterations at grain boundaries. Strained quartz grains from metamorphic rocks show a so-called "undulatory extinction" (Blatt and Christie, 1963).
Quartz is one of the few minerals on Mindat where "visual identification" may be accepted as a method of identification for new locality entries and photos of well-formed crystals. In other cases, at least hardness should be checked, too.
For quartz as a rock-forming mineral visual identification is often insufficient.
Quartz normally does not require special attention when handled or stored. At ambient conditions, quartz is chemically almost inert, so it does not suffer from the problems seen in many other minerals. Crystals do not disintegrate or crumble, they do not oxidize or dissolve easily in water and they don't mind being touched. The only problem for the collector is dust, which will find and cover your crystals, no matter what you do.
Quartz crystals that contain large fluid or gas inclusions may crack when heated - skeleton quartz is the most sensitive variety in this respect - but most quartz specimens can take some heat, like cleaning in warm water, without being damaged.
Quartz is hard but quite brittle, and with some effort, one can damage a crystal even with things that are much softer. The edges of the crystals are very often slightly damaged because crystals were not kept separate from each other.
Colored quartz varieties can pale in sunlight, the most sensitive variety is euhedral rose quartz/pink quartz, which should be kept in the dark. Amethyst, smoky quartz and natural citrine will also pale, but it takes very long.
Mild ultrasonic cleaning is usually not a problem as long the crystals are not internally cracked, but some varieties may be damaged, in particular, amethyst (due to its polysynthetic Brazil law twinning) and skeleton quartz with liquid and gas inclusions.
Rock Currier wrote a Mindat article on cleaning quartz that is worthwhile reading: http://www.mindat.org/article.php/403/Cleaning+Quartz
When cutting, grinding and polishing specimens, keep in mind that quartz dust will cause silicosis (for a review, see Goldsmith, 1994), do not cut or grind dry and wear an appropriate dust mask.
Quartz bear, on average, 10 ppmw (5 ppmw median) of water. Crystals rich in OH defects may bear as much as 250 ppmw (maximum).
The Si analogue of pertoldite.
Macro- and Cryptocrystalline Quartz
Quartz occurs in two basic forms:
1. The more common macrocrystalline quartz is made of visible crystals or grains. Examples are rock crystals, the grains in sandstone, but also massive quartz that is made of large crystallites without any crystal faces, like vein quartz.
2. Cryptocrystalline quartz or microcrystalline quartz is made of dense and compact aggregates of microscopic quartz crystals and crystallites. Examples are agate and chert. The different types of cryptocrystalline quartz are colloquially subsumed under the term chalcedony, although that term has a more strict definition in scientific literature. It is worth mentioning that most chalcedony contains small amounts of another SiO2 polymorph, moganite, so it is not always pure quartz.
Quartz Varieties
Quartz crystals or aggregates that share certain peculiar physical properties have been classified as quartz varieties with specific "trivial names".
The best known examples are the colored varieties of quartz, like amethyst or smoky quartz, but there are also trivial names for specific crystal shapes, aggregates and textures, like scepter quartz, gwindel or quartzine. Because there are no canonical rules on naming or defining quartz varieties like they are for minerals, the definitions of some quartz varieties are precise and generally accepted, while the definitions of others vary considerably between different authors, or are rather fuzzy.
Mindat Classification of Quartz Varieties
On Mindat, macrocrystalline quartz and its varieties are listed as quartz and varieties of quartz.
Cryptocrystalline quartz and its varieties are listed as chalcedony, like "Quartz (Var: Chalcedony)", or as variety of chalcedony, like "Chalcedony (Var: Agate)".
More about the specific properties of chalcedony and its varieties can be found at the respective mineral pages.
Note that, contrary to minerals, the definitions of varieties are not mutually exclusive in the sense that no mineral can be another. A single specimen can be correctly classified as several varieties.
Structure of Quartz
The structure of quartz was deciphered by Bragg and Gibbs in 1925 (for a review of the structure and symmetry features of quartz, see Heaney, 1994). Its basic building block is the SiO4 group, in which four oxygen atoms surround a central silicon atom to form a tetrahedron. Since each oxygen is member of two SiO4 groups, the formula of quartz is SiO2. The SiO4 tetrahedra form a three-dimensional network and many mineralogy textbooks classify quartz as a network silicate or tectosilicate.Quartz can be thought of as being made of threefold and sixfold helical chains of SiO4 tetrahedra that run parallel to the c axis. Figure 1 shows two representations of a threefold SiO4 helix and its relationship to the quartz unit cell: to the right a ball model with red oxygen and white silicon atoms, to the left a tetrahedral model, with the corners of the tetrahedra at the position of the oxygen atoms.
Six of such helices are connected to form a ring that surrounds a central channel which runs parallel to the c-axis, sometimes called "c-channel". The SiO4 tetrahedra around the central c-channel form two independent sixfold helices. Figure 2 shows two views of the corresponding structure: looking in the direction of the c-axis in the top row, and looking in the direction of an a-axis in the bottom row. Like quartz crystals, the ring is six-sided but has a trigonal symmetry. The large channels are an important structural feature of quartz because they may be occupied by small cations.
You can explore the crystal structure of quartz with the interactive tool JSmol further down this page.
Handedness of Quartz Crystals
A helix is either turning clockwise (right-handed) or counter-clockwise (left-handed). Due to the helical arrangement of the SiO4 tetrahedra, the atomic lattice of quartz possesses the symmetry properties of a helix: Quartz forms left- and right-handed crystals, whose crystal structure and morphology are mirror-images of each other.
In a crystal with space group P3121 (right), the sixfold helices turn counter-clockwise (left) and the threefold helices clockwise (right).
In a crystal with space group P3221 (left), the sixfold helices turn clockwise (right) and the threefold helices counter-clockwise (left).
For a thorough review of the symmetry features of quartz, see Heaney (1994).
The crystallographic form of quartz that is characteristic for its symmetry properties is the trigonal trapezohedron. The position of the faces of the positive trigonal trapezohedra on the crystal reflects the handedness of the structure of the crystal. The figure to the right visualizes the relationship between the handedness of the six-fold helices and the position of the faces of the positive trigonal trapezohedron (x - orange) and the trigonal bipyramid (s - blue). Unfortunately, these faces are not present on all crystals, and often it is not possible to determine the handedness of a crystal from its morphology.
Quartz is optically active: the polarization of a light ray passing through a crystal parallel to the c-axis will be rotated either to the left or the right, depending on the handedness of the crystal (Arago, 1811; Biot, 1812; Herschel, 1822). The relationship between handedness of the crystals and the symmetry of the structure and hence the optical rotation was determined by de Vries (1958).
The following table lists how symmetry, morphology and optical behaviour are related.
Note that the morphological handedness as expressed by the position of the trapezohedral and bipyramidal faces x and s does not match the symmetry's handedness:
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Morphology
Quartz is found as individual crystals and as crystal aggregates. Well crystallized quartz crystals are typically six-sided prisms with steep pyramidal terminations. They can be stubby ("short prismatic") or elongated and even needle-like. In most environments quartz crystals are attached to the host rock and only have one tip, but double-terminated crystals are also found.
As a rock-forming mineral, quartz commonly occurs as sub-millimeter to centimeter-sized anhedral grains, well-formed crystals are uncommon. Secondary vein-fillings of quartz are typically massive.
Quartz belongs to the trigonal-trapezohedral crystal class 32. Of the seven basic crystallographic forms of this crystal class, the hexagonal prism and trigonal rhombohedra are very common and determine the overall shape of the crystals. The trigonal bipyramids and trigonal trapezohedra are frequently found, but typically only as relatively small faces. The trigonal prisms, the basal pinacoid and in particular ditrigonal prisms are very rare (Frondel, 1962).
Quartz crystals show about 100 different crystallographic forms in nature (Frondel, 1962; Rykart, 1995). It is convenient and common practice to designate them with Latin and Greek letter symbols instead of Miller-Bravais indices. The following figure illustrates the relation of the common forms (sorted by abundance) to the faces found on quartz crystals. The most common combination of crystallographic forms in quartz crystals is r+m+z.
The handedness of quartz crystals can be determined easily from the positions of x faces, which are at the lower left or lower right corner of the r face (orange faces in Fig.5). With some difficulty the handedness can be determined from the position of the s faces (blue faces in Fig.5), which lie between the r and z faces: the s face often shows a fine striation that runs parallel to the edge of the r-face.
The bottom row shows a top view of the crystals. It does not only show their trigonal symmetry but also the chirality of the position of the x faces.
Macroscopic Structure of Quartz Crystals
In response to lattice defects, and apparently reflecting their growth conditions, quartz crystals may develop two very distinct and mutually exclusive types of internal structure:
- Macromosaic Structure, sometimes called "Friedlaender Quartz"
- Lamellar Structure, sometimes called "Bambauer Quartz"
Individual crystals may possess both structural types, but the respective parts of the crystals grew at different developmental stages (Hertweck et al., 1998). It is sometimes claimed that all quartz occurs either as macromosaic or as lamellar structural type. This is not correct.
The lamellar structure was first described by Weil (1931). The crystals contain layers that show an optical anomaly: they are biaxial. The layers are stacked parallel to the crystal faces in an onion-like manner and were found to be associated with a relatively high hydrogen and aluminium content (Bambauer et al., 1961, 1962, 1963). Lamellar quartz cannot be safely recognized without studying the optical properties of the crystal in a thin section.
Macromosaic quartz crystals have been described by Friedlaender (1951) and are composed of slightly tilted and radially arranged wedge-shaped sectors. They are recognized by the presence of sutures on the crystal faces which are often confused with twin boundaries. Crystals with such a structure are found in pegmatite and miarole pockets and in high-temperature alpine-type fissures.
Quartz Crystal Habits
Strictly speaking, the term "habit" is used to designate the overall shape of individual crystals, regardless of the crystallographic forms (crystal faces) involved. Confusingly, the definitions of some habits of quartz crystals do include specific forms. Many of the trivial names of these habits have been introduced and popularized by rock hounds in the Alps (for a good overview, see Rykart, 1995). The most important habits with trivial names (with synonyms in different languages in braces) are:
a) Normal habit ("Maderaner Habitus", prismatic habit): "typical" quartz crystals that are not or only slightly tapered.
b) Trigonal habit: Crystals with obvious trigonal symmetry, for example, because of missing z faces, or because of a triangular cross section, like in crystals with a Muzo habit (h).
c) Pseudohexagonal habit: Crystals with an even development of rhombohedral and prism faces.
d) Cumberland habit: Crystals with very small or absent prism faces, often bipyramidal.
e) Pseudocubic quartz (pseudocubic habit, cubic habit, cube quartz, "Würfelquarz"): Crystals with a dominant r or z form that look like slightly distorted cubes.
f) Dauphiné habit: Crystal tips with a single very dominant rhombohedral face.
g) Tessin habit ("Abito Ticino", "Tessiner Habitus", "Rauriser Habitus", "Penninischer Habitus", "Acute Rhombohedral Habit"): Crystals that are tapered by steep rhombohedral faces { h 0 i 1 }, Tessin habit in the strict sense is dominated by { 4 0 4 1 } and { 3 0 3 1 } faces. At the original locality, they possess a macromosaic structure.
h) Muzo habit: Crystals with prism faces that are tapered under the z faces because these are made of a succession of alternating m and z faces, and who have a trigonal cross section at the crystal tips (Gansser, 1963).
Needle quartz (acicular habit): Crystals greatly elongated along the c-axis.
Quartz Growth Forms
In addition to crystallographic forms and habits, many quartz crystals are characterized by peculiar morphological features that reflect different modes of growth during their development. Some of these "growth forms" are found at many different localities and - like habits - have been given "trivial names" (e.g., "cactus quartz", "gwindel"). Some of these are listed as varieties of quartz on Mindat. Among the more common and important growth forms are:
Sceptre quartz: Crystals with syntaxial overgrowth of a second generation tip.
Faden quartz: Crystals and crystal aggregates with a white thread running through the crystals. The thread is caused by repetitive cracking of the crystal during growth and consists of fluid inclusions.
Window or Skeleton or Frame or Fenster quartz: Crystals with frame-like, elevated edges of the crystal faces, usually with parallel grown blades that grow from the edges to the center of the faces in a window glass-like manner. Hopper crystals that correspond to skeleton-growth in the strict sense are rare.
Phantom quartz: Crystals in which outlines of the shape of earlier developmental stages of the crystal are visible because of inclusions or color zones.
Sprouting quartz ("Sprossenquarz"): Crystals on which split-growth causes subparallel daughter crystals to sprout from the crystal faces
Artichoke quartz: A form of split-growth resulting in specimens with composite artichoke-like crystal tips.
Gwindel: Crystals elongated and twisted along an a-axis.
Cactus quartz or spirit quartz: Crystals whose prism faces are covered by small, roughly radially grown second-generation crystals.
Quartz Twins
Twinning is very common in quartz, but is often inconspicuous and difficult to recognize. Two types of twinning can be distinguished (data in tables from Jentzsch, 1867, 1868; Gault, 1949; Frondel, 1962):
1. Twins with parallel main crystallographic axes
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Dauphiné and Brazil law twins are very common. Most crystals, even if morphologically untwinned, contain at least small twin domains. Both types of twins can be found in a single crystal.
Dauphiné Law
Also called: Swiss Law, Alpine Law
Dauphiné law twins can be thought of as a merger of two crystals of equal handedness that are rotated by 60° around the c-axis relative to each other (Weiss, 1816). They are penetration twins composed of twin domains with irregular boundaries (Leydolt, 1855). The size and shape of the twin domains can vary and the shares of the twin domains in a crystal do not have to be equal. The degree of intergrowth of the domains may increase during growth, starting from roughly triangular sectors at the base to complex irregular patterns at the tip of the crystal (Friedlaender, 1951). Twin domains are only rarely visible in natural crystals and normally need to get visualized by etching the surface or a polished cross-section (Leydolt, 1855; Judd, 1888). Electron microscopical studies reveal that on a small scale the twin domains look like complex polygons with straight boundaries (Lang, 1965; McLaren and Phakey, 1969).
Dauphiné twins can sometimes be recognised by the position and arrangement of crystal faces, in particular, the x-faces. Because the rhombohedral faces are composites of r and z faces, they do not show the common size difference of the faces and the crystals assume a pseudohexagonal habit.
Rarely Dauphiné twinned crystals that lack one type of rhombohedral face (either r or z) - and that would display a trigonal habit if they were untwinned - show re-entrant angles at the tip that make them look like drill heads (for example, Schäfer, 1999).
Dauphiné twins are sometimes called electrical twins, because this kind of twinning reduces or even suppresses the piezoelectricity that is typical for untwinned quartz crystals, while their optical activity remains unaffected (Thomas, 1945; Donnay and Le Page, 1975).
Brazil Law
Also called: Optical Law
Brazil law twins can be thought of as a merger of a left- and right-handed crystal: they are penetration twins composed of left- and right-handed domains. Their twin boundaries are usually straight lines, resulting in a characteristic pattern made of straight lines and triangles (Leydolt, 1855). As with Dauphiné twins, the twin domains are usually not visible in natural crystals and need to be visualized by etching (Leydolt, 1855). The corresponding surface patterns on crystal faces are polygonal patches with straight boundaries, often triangular.
Brazil law twins that show the ideal arrangement of x and s crystal faces are very rare.
Many amethysts are twinned polysynthetically according to the Brazil Law: Parts of the amethyst crystals, in particular in zones under the r rhombohedral faces are composed of alternating layers of left- and right-handed quartz (Brewster 1823; McLaren and Pitkethly, 1982; Taijing and Sunagawa, 1990). The gauge of individual layers is normally less than 1 mm. The layered structure may be visible as a fingerprint-like pattern on rhombohedral faces.
Brazil law twins are sometimes called optical twins, because this kind of twinning reduces or even suppresses the optical activity typical for quartz crystals. Confusingly, and contrary to common belief, Brazil law twinning does also reduce or suppress the piezoelectricity of quartz crystals (Thomas, 1945; Donnay and Le Page, 1975).
Combined Law
Also called: Liebisch Law, Dauphiné-Brazil Law, Leydolt Law
It is not unusual for crystals to show Dauphiné and Brazil law domains in one crystal, and sometimes crystals show x or s faces at positions that would indicate a special type of twinning. Electron microscopic studies show that when Brazil law twins are heated and develop new Dauphiné twin domains, their left- and right-handed domains do not share boundaries when they are rotated with respect to each other (Van Goethem et al., 1977), so Liebisch twinning seems to be energetically less favorable. Accordingly, Liebisch twinning is rare.
2. Twins with inclined main crystallographic axes (incomplete list)
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Fig.9: Twins with Inclined Axes.
a) Japan Law
b) Breithaupt Law
c) Reichenstein-Grieserntal Law
d) Zinnwald Law
a) Japan Law
b) Breithaupt Law
c) Reichenstein-Grieserntal Law
d) Zinnwald Law
Japan Law
Also called: Weiss Law, La Gardette Law
Japan law twins are the only common quartz twins with inclined c axes. The law was first found and described by Weiss (1829) on crystals from La Gardette, France, but the name "Japan law" became more popular after a great number of them were found in Japan. The c-axis of two crystals meet at an angle of 84°33', with two of the m prism faces of both crystals being parallel. The twinning plane {1 1 2 2} of Japan law twins corresponds to the flat trigonal bipyramid ξ (the Greek letter xi).
Japan law twins are contact twins (Sunagawa and Yasuda, 1983). The twin junctions often look jagged on the crystal surface, but are perfectly straight in the interior of the crystals, and form a thin plane that runs from the base of the crystal to the V-shaped indentation between the branches (Sunagawa and Yasuda, 1983). Electron microscopic studies revealed that the twin boundary also forms a perfect plane parallel to {1 1 2 2} (Lenart et al. 2012; Momma et al. 2015), but appears to be restricted to the initial growth periods of the crystal, extending only a few hundred micrometers, which has been interpreted as an indication of a formation as a nucleation twin (Lenart et al. 2012). The cause of the twin formation is still not understood.
Most Japan law twins are flattened, and often they are larger than untwinned crystals that accompany them. Depending on the handedness of the two branches of a twin, one can distinguish 8 different basic twinning subtypes that are also twinned according to the Brazil or Dauphiné law (Frondel, 1962), but the pattern of Brazil and Dauphiné twin domains can be very complex (Kozu, 1952).
Colored Quartz Varieties
Compared to many other minerals, quartz is chemically very pure, most crystals contain more than 99.5% SiO2. Nevertheless, varieties colored by impurities occur. These can be devided into two groups:
1. Quartz colored by trace elements built into the crystal lattice.
Only a few elements can replace silicon in the quartz lattice (substitutional positions) or are small enough to occupy free spaces in the lattice (interstitial positions). In natural quartz crystals, the most common ones to replace Si are Al, Fe, Ge, and Ti, whereas Li, Na, Ca, Mg and Fe often occupy interstitial positions in the "c-channels" mentioned under "Structure of Quartz". Of the substitutional trace elements, only Al, Fe and more rarely P are found to play a role in natural colored varieties. There are only a handful of quartz varieties colored by trace elements built into the lattice, sorted by abundance, with the more common ones first:
- Smoky quartz
- Amethyst
- Citrine
- Pink Quartz / Euhedral Rose Quartz
- Prasiolite
With the possible exception of some prasiolites and some citrines, the color of these varieties is based on color centers whose formation requires high energy irradiation from radioactive elements in the surrounding rocks (O'Brien, 1955; Lehmann and Moore, 1966; Maschmeyer et al., 1980; Maschmeier and Lehmann, 1983). Quartz varieties based on color centers are pleochroic, and their color centers can be destroyed by heat treatment.
Note that individual quartz crystals may contain several colored varieties, like an amethyst with smoky zones.
2. Quartz colored by inclusions of separate phases, for example minerals or fluids.
Because quartz crystals grow in many geological environments, they embed many different minerals during growth and assume the colors of the included minerals. Colors may also be caused by light scattering at finely distributed but colorless inclusions.
There are also trivial names for varieties colored by inclusions that have been found at many localities, like "prase", "ferruginous quartz" or "rose quartz". However, the definitions of these varieties are often rather fuzzy, and different authors use different definitions.
Occurrence of Quartz
Quartz is one of the crystalline forms of silica, the essential building material for all silicates, and quartz can only form where silica is present in excess of what is consumed in the formation of other silicate minerals.
Quartz may also be consumed during the formation of new silicate minerals, in particular at higher temperatures and pressures, and certain geological environments are "incompatible" with free silica and hence quartz.
Quartz as a Rock-Forming Mineral
Silica has been enriched in the continental Earth's crust to about 60% (Rudnick and Gao, 2003) by processes like magmatic differentiation and the formation of silica-rich igneous rocks (mainly driven by plate tectonics) and the accumulation of the physically and chemically stable quartz in sediments and sedimentary rocks. The oceanic crust's silica content of about 50% (White and Klein, 2014) in its igneous rocks is too low for quartz to form in them.
The largest amount of quartz is found as a rock-forming mineral in silica-rich igneous rocks, namely granite-like plutonic rocks, and in the metamorphic rocks that are derived from them. Under conditions at or near the surface, quartz is generally more stable than most other rock-forming minerals and its accumulation in sediments leads to rocks that are highly enriched in quartz, like sandstones. Quartz is also a major constituent of sedimentary rocks whose high quartz content is not immediately obvious, like slates, as well as in the metamorphic rocks derived from such quartz-bearing precursor rocks.
Quartz Veins
At higher temperatures and pressures quartz is easily dissolved by watery fluids percolating the rock. When silica-rich solutions penetrate cooler rocks, the silica will precipitate as quartz in fissures, forming thin white seams as well as large veins which may extend over many kilometers (Bons, 2001; Wangen and Munz, 2004, Pati et al, 2007). In most cases, the quartz in these veins will be massive, but they may also contain well-formed quartz crystals. Phyllites and schists often contain thin lenticular or regular veins of so-called "segregation quartz" (Vinx, 2013) that run parallel to the bedding and are the result of local transport of silica during metamorphosis (Chapman, 1950; Sawyer and Robin, 1986). Silica-rich fluids are also driven out of solidifying magma bodies. When these hot brines enter cooler rocks, the solution gets oversaturated in silica, and quartz forms.
Along with the silica, metals are also transported with the brines and precipitate in the veins as sometimes valuable ore minerals. The association of gold and quartz veins is a well-known example. Quartz is the most common "gangue mineral" in ore deposits.
Quartz Crystals
Quartz crystals typically grow in fluids at elevated temperatures between 150°C and 600°C, but they also grow at ambient conditions (Mackenzie and Gees, 1971; Ries and Menckhoff, 2008).
Quartz is best known for the beautiful crystals it forms in all sorts of cavities and fissures. The greatest variety of shapes and colors of quartz crystals comes from hydrothermal ore veins and deposits, reflecting large differences in growth conditions in these environments (chemistry, temperature, pressure). Splendid, large crystals grow from ascending hot brines in large fissures, from residual silica-rich fluids in cavities in pegmatites and from locally mobilized silica in Alpine-type fissures. An economically important source of amethyst for the lapidary industry are cavities of volcanic rocks. Small, but well-formed quartz crystals are found in septarian nodules, and in dissolution pockets in limestones.
Well-formed quartz crystals that are fully embedded in sedimentary rocks and grew during diagenesis (so-called authigenic quartz crystals) are occasionally found in limestones, marls, and evaporites (e.g. Rykart, 1984).
Euhedral quartz crystals that are embedded in igneous rocks are uncommon. Quartz is among the last minerals that form during the solidification of a magma, and because the crystals fill the residual space between the older crystals of other minerals they are usually irregular. Euhedral, stubby bipyramidal quartz crystals are occasionally found in rhyolites. These are usually paramorphs after beta-quartz with hexagonal symmetry, quartz crystals whose trigonal habit shows that they grew as alpha-quartz are very rare in volcanic rocks (e.g. Flick and Weissenbach, 1978). Only rarely are euhedral quartz crystals seen embedded in metamorphic rocks (Kenngott, 1854; Tschermak, 1874; Heddle, 1901).
Identification
In most cases quartz is easy to identify by its combination of the following properties:
- hardness (easily scratches glass, also harder than steel)
- glass-like luster
- poor to indistinct cleavage
- conchoidal fracture in crystals, in massive specimens the fracture often looks irregular to the naked eye, but still conchoidal at high magnification.
Note that in macrocrystalline quartz the fracture surfaces have a vitreous to resinous luster, whereas in cryptocrystalline quartz (chalcedony) fractured surfaces are dull.
Crystals are very common and their usually six-sided shape and six-sided pyramidal tips are well-known. Intergrown crystals without tips can often be recognized by the presence of the characteristic striation on the prism faces.
Quartz as a rock-forming mineral, in particular as irregular grains in the matrix, occasionally poses problems and may require additional means of identification. It may be confused with cordierite (pleochroic, tendency to alteration) and nepheline (lower hardness, geological environment incompatible with quartz).
In thin sections macrocrystalline quartz appears clear and homogeneous, with blue-gray to white or bright yellow interference colors and a low relief. Quartz does not show alterations at grain boundaries. Strained quartz grains from metamorphic rocks show a so-called "undulatory extinction" (Blatt and Christie, 1963).
ID Requirements on Mindat
Quartz is one of the few minerals on Mindat where "visual identification" may be accepted as a method of identification for new locality entries and photos of well-formed crystals. In other cases, at least hardness should be checked, too.
For quartz as a rock-forming mineral visual identification is often insufficient.
Handling Quartz
Quartz normally does not require special attention when handled or stored. At ambient conditions, quartz is chemically almost inert, so it does not suffer from the problems seen in many other minerals. Crystals do not disintegrate or crumble, they do not oxidize or dissolve easily in water and they don't mind being touched. The only problem for the collector is dust, which will find and cover your crystals, no matter what you do.
Quartz crystals that contain large fluid or gas inclusions may crack when heated - skeleton quartz is the most sensitive variety in this respect - but most quartz specimens can take some heat, like cleaning in warm water, without being damaged.
Quartz is hard but quite brittle, and with some effort, one can damage a crystal even with things that are much softer. The edges of the crystals are very often slightly damaged because crystals were not kept separate from each other.
Colored quartz varieties can pale in sunlight, the most sensitive variety is euhedral rose quartz/pink quartz, which should be kept in the dark. Amethyst, smoky quartz and natural citrine will also pale, but it takes very long.
Mild ultrasonic cleaning is usually not a problem as long the crystals are not internally cracked, but some varieties may be damaged, in particular, amethyst (due to its polysynthetic Brazil law twinning) and skeleton quartz with liquid and gas inclusions.
Rock Currier wrote a Mindat article on cleaning quartz that is worthwhile reading: http://www.mindat.org/article.php/403/Cleaning+Quartz
When cutting, grinding and polishing specimens, keep in mind that quartz dust will cause silicosis (for a review, see Goldsmith, 1994), do not cut or grind dry and wear an appropriate dust mask.
Quartz bear, on average, 10 ppmw (5 ppmw median) of water. Crystals rich in OH defects may bear as much as 250 ppmw (maximum).
Visit gemdat.org for gemological information about Quartz.
Unique Identifiers
Mindat ID:
3337
Long-form identifier:
mindat:1:1:3337:0
GUID
(UUID V4):
(UUID V4):
4ca61d6f-75f8-4208-8fb2-3b0eecbcd8f0
Classification of Quartz
Approved, 'Grandfathered' (first described prior to 1959)
4.DA.05
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
A : With small cations: Silica family
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
A : With small cations: Silica family
Dana 7th ed.:
75.1.3.1
75.1.3.1
75 : TECTOSILICATES Si Tetrahedral Frameworks
1 : Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
75 : TECTOSILICATES Si Tetrahedral Frameworks
1 : Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
7.8.1
7 : Oxides and Hydroxides
8 : Oxides of Si
7 : Oxides and Hydroxides
8 : Oxides of Si
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Symbol | Source | Reference |
---|---|---|
Qz | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Qtz | Kretz (1983) | Kretz, R. (1983) Symbols of rock-forming minerals. American Mineralogist, 68, 277–279. |
Qtz | Siivolam & Schmid (2007) | Siivolam, J. and Schmid, R. (2007) Recommendations by the IUGS Subcommission on the Systematics of Metamorphic Rocks: List of mineral abbreviations. Web-version 01.02.07. IUGS Commission on the Systematics in Petrology. download |
Qz | Whitney & Evans (2010) | Whitney, D.L. and Evans, B.W. (2010) Abbreviations for names of rock-forming minerals. American Mineralogist, 95, 185–187 doi:10.2138/am.2010.3371 |
Qtz | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Qz | Warr (2020) | Warr, L.N. (2020) Recommended abbreviations for the names of clay minerals and associated phases. Clay Minerals, 55, 261–264 doi:10.1180/clm.2020.30 |
Pronunciation of Quartz
Pronunciation:
Play | Recorded by | Country |
---|---|---|
Jolyon & Katya Ralph | United Kingdom |
Physical Properties of Quartz
Vitreous
Transparency:
Transparent, Translucent
Colour:
Colorless, purple, rose, red, black, yellow, brown, green, blue, orange, etc.
Streak:
White
Hardness:
7 on Mohs scale
Hardness Data:
Mohs hardness reference species
Comment:
Some variability by direction.
Tenacity:
Brittle
Cleavage:
Poor/Indistinct
The rhombohedral cleavage r{1011} is most often seen, there are at least six others reported.
The rhombohedral cleavage r{1011} is most often seen, there are at least six others reported.
Fracture:
Conchoidal
Comment:
Tough when massive
Density:
2.65 - 2.66 g/cm3 (Measured) 2.66 g/cm3 (Calculated)
Optical Data of Quartz
Type:
Uniaxial (+)
RI values:
nω = 1.544(1) nε = 1.553(1)
Birefringence:
Max Birefringence:
δ = 0.009
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Low
Dispersion:
low
Comments:
Varieties colored by trace elements built into the crystal lattice, as opposed to varieties colored by inclusions, generally show dichroism: smoky quartz, amethyst, citrine, prasiolite, "rose quartz in crystals" (a.k.a. pink quartz), are pleochroic.
Chemical Properties of Quartz
Formula:
SiO2
Elements listed:
Common Impurities:
H,Al,Li,Fe,Ti,Na,Mg,Ge,etc
Age distribution
Recorded ages:
Phanerozoic : 279 ± 3 Ma to 55.7 Ma - based on 7 recorded ages.
Crystallography of Quartz
Crystal System:
Trigonal
Class (H-M):
3 2 - Trapezohedral
Space Group:
P31 2 1
Cell Parameters:
a = 4.9133 Å, c = 5.4053 Å
Ratio:
a:c = 1 : 1.1
Unit Cell V:
113.00 ų (Calculated from Unit Cell)
Z:
3
Twinning:
Dauphiné law.
Brazil law.
Japan law.
Others for beta-quartz...
Brazil law.
Japan law.
Others for beta-quartz...
Comment:
Space group is P3121 for left-handed crystals and P3221 for right-handed crystals
Crystallographic forms of Quartz
Crystal Atlas:
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
---|---|---|---|---|---|---|---|
0000789 | Quartz | Levien L, Prewitt C T, Weidner D J (1980) Structure and elastic properties of quartz at pressure American Mineralogist 65 920-930 | 1980 | 0 | 293 | ||
0000790 | Quartz | Levien L, Prewitt C T, Weidner D J (1980) Structure and elastic properties of quartz at pressure American Mineralogist 65 920-930 | 1980 | 2.07 | 293 | ||
0000791 | Quartz | Levien L, Prewitt C T, Weidner D J (1980) Structure and elastic properties of quartz at pressure American Mineralogist 65 920-930 | 1980 | 3.76 | 293 | ||
0000792 | Quartz | Levien L, Prewitt C T, Weidner D J (1980) Structure and elastic properties of quartz at pressure American Mineralogist 65 920-930 | 1980 | 4.86 | 293 | ||
0000793 | Quartz | Levien L, Prewitt C T, Weidner D J (1980) Structure and elastic properties of quartz at pressure American Mineralogist 65 920-930 | 1980 | 5.58 | 293 | ||
0000794 | Quartz | Levien L, Prewitt C T, Weidner D J (1980) Structure and elastic properties of quartz at pressure American Mineralogist 65 920-930 | 1980 | 6.14 | 293 | ||
0004265 | Quartz | Ikuta D, Kawame N, Banno S, Hirajima T, Ito K, Rakovan J F, Downs R T, Tamada O (2007) First in situ X-ray diffraction identification of coesite and retrograde quartz on a glass thin section of an ultrahigh-pressure metamorphic rock and their crystal structure details American Mineralogist 92 57-63 | 2007 | Yangkou meta-igneous complex in the middle part of the Sulu UHP terrain, eastern China | 0 | 293 | |
0004266 | Quartz | Ikuta D, Kawame N, Banno S, Hirajima T, Ito K, Rakovan J F, Downs R T, Tamada O (2007) First in situ X-ray diffraction identification of coesite and retrograde quartz on a glass thin section of an ultrahigh-pressure metamorphic rock and their crystal structure details American Mineralogist 92 57-63 | 2007 | Oomine granite, Tenkawa-mura, Nara, Southwest Japan | 0 | 293 | |
0004267 | Quartz | Ikuta D, Kawame N, Banno S, Hirajima T, Ito K, Rakovan J F, Downs R T, Tamada O (2007) First in situ X-ray diffraction identification of coesite and retrograde quartz on a glass thin section of an ultrahigh-pressure metamorphic rock and their crystal structure details American Mineralogist 92 57-63 | 2007 | Oomine granite, Tenkawa-mura, Nara, Southwest Japan | 0 | 293 | |
0006212 | Quartz | Antao S M, Hassan I, Wang J, Lee P L, Toby B H (2008) State-of-the-art high-resolution powder x-ray diffraction (HRPXRD) illustrated with Rietveld structure refinement of quartz, sodalite, tremolite, and meionite The Canadian Mineralogist 46 1501-1509 | 2008 | not specified | 0 | 293 | |
0006362 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 298 | ||
0006363 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 398 | ||
0006364 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 498 | ||
0006365 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 597 | ||
0006366 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 697 | ||
0006367 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 773 | ||
0006368 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 813 | ||
0006369 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 838 | ||
0006370 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 848 | ||
0006371 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 854 | ||
0006372 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 859 | ||
0006373 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 869 | ||
0006374 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 891 | ||
0006375 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 920 | ||
0006376 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 972 | ||
0006377 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 1012 | ||
0006378 | Quartz | Kihara K (1990) An X-ray study of the temperature dependence of the quartz structure European Journal of Mineralogy 2 63-77 | 1990 | 0 | 1078 | ||
0008971 | Quartz | Rosa A L, El-Barbary A A, Heggie M I, Briddon P R (2005) Structural and thermodynamic properties of water related defects in alpha-quartz Physics and Chemistry of Minerals 32 323-331 | 2005 | 0 | 293 | ||
0018071 | Quartz | Wyckoff R (1926) Kriterien fur hexagonale Raumgruppen und die Kristallstruktur von beta Quarz. _cod_database_code 1011200 Zeitschrift fur Kristallographie 63 507-537 | 1926 | 0 | 293 | ||
0017992 | Quartz | Wei (1935) Die Bindung im Quarz _cod_database_code 1011097 Zeitschrift fur Kristallographie 92 355-362 | 1935 | 0 | 293 | ||
0010604 | Quartz | Arnold H (1962) Die struktur des hochquarzes Zeitschrift fur Kristallographie 117 467-469 | 1962 | 0 | 293 | ||
0010605 | Quartz | Arnold H (1962) Die struktur des hochquarzes Zeitschrift fur Kristallographie 117 467-469 | 1962 | 0 | 293 | ||
0011007 | Quartz | Glinnemann J, King H E, Schulz H, Hahn T, La Placa S J, Dacol F (1992) Crystal structures of the low-temperature quartz-type phases of SiO2 and GeO2 at elevated pressure Zeitschrift fur Kristallographie 198 177-212 | 1992 | 0 | 293 | ||
0011008 | Quartz | Glinnemann J, King H E, Schulz H, Hahn T, La Placa S J, Dacol F (1992) Crystal structures of the low-temperature quartz-type phases of SiO2 and GeO2 at elevated pressure Zeitschrift fur Kristallographie 198 177-212 | 1992 | 4 | 293 | ||
0011009 | Quartz | Glinnemann J, King H E, Schulz H, Hahn T, La Placa S J, Dacol F (1992) Crystal structures of the low-temperature quartz-type phases of SiO2 and GeO2 at elevated pressure Zeitschrift fur Kristallographie 198 177-212 | 1992 | 7.2 | 293 | ||
0011010 | Quartz | Glinnemann J, King H E, Schulz H, Hahn T, La Placa S J, Dacol F (1992) Crystal structures of the low-temperature quartz-type phases of SiO2 and GeO2 at elevated pressure Zeitschrift fur Kristallographie 198 177-212 | 1992 | 10.2 | 293 | ||
0012866 | Quartz | Gualtieri A F (2000) Accuracy of XRPD QPA using the combined Rietveld-RIR method Journal of Applied Crystallography 33 267-278 | 2000 | Baveno, Novara, Italy | 0 | 293 | |
0018749 | Quartz | Gibbs G V, Boisen M B, Downs R T, Lasaga A C (1988) Mathematical Modeling of the structures and bulk moduli of TX2 quartz Materials Research Society Symposia Proceedings 121 155-165 | 1988 | theoretical | 0 | 293 | |
0018049 | Quartz | Brill R, Hermann C, Peters C (1939) Studien ueber chemische Bindung mittels Fourieranalyse III. Die Bindung im Quarz _cod_database_code 1011172 Naturwissenschaften 27 676-677 | 1939 | 0 | 293 | ||
0015462 | Quartz | Hazen R M, Finger L W, Hemley R J, Mao H K (1989) High-pressure crystal chemistry and amorphization of alpha-quartz Solid State Communications 72 507-511 | 1989 | synthetic | 0 | 293 | |
0015463 | Quartz | Hazen R M, Finger L W, Hemley R J, Mao H K (1989) High-pressure crystal chemistry and amorphization of alpha-quartz Solid State Communications 72 507-511 | 1989 | synthetic | 2 | 293 | |
0015464 | Quartz | Hazen R M, Finger L W, Hemley R J, Mao H K (1989) High-pressure crystal chemistry and amorphization of alpha-quartz Solid State Communications 72 507-511 | 1989 | synthetic | 5.1 | 293 | |
0015465 | Quartz | Hazen R M, Finger L W, Hemley R J, Mao H K (1989) High-pressure crystal chemistry and amorphization of alpha-quartz Solid State Communications 72 507-511 | 1989 | synthetic | 8 | 293 | |
0015466 | Quartz | Hazen R M, Finger L W, Hemley R J, Mao H K (1989) High-pressure crystal chemistry and amorphization of alpha-quartz Solid State Communications 72 507-511 | 1989 | synthetic | 9.5 | 293 | |
0015467 | Quartz | Hazen R M, Finger L W, Hemley R J, Mao H K (1989) High-pressure crystal chemistry and amorphization of alpha-quartz Solid State Communications 72 507-511 | 1989 | synthetic | 12.5 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Image Loading
Radiation - Copper Kα
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
4.257 Å | (22) |
3.342 Å | (100) |
2.457 Å | (8) |
2.282 Å | (8) |
1.8179 Å | (14) |
1.5418 Å | (9) |
1.3718 Å | (8) |
Geological Environment
Paragenetic Mode(s):
Geological Setting:
Most of them...
Synonyms of Quartz
Other Language Names for Quartz
Arabic:مرو
Bosnian:Kvarc
Bulgarian:Кварц
Catalan:Quars
Croatian:Kvarc
Czech:Křemen
Danish:Kvarts
Dutch:Kwarts
Esperanto:Kvarco
Estonian:Kvarts
Farsi/Persian:کوارتز
Finnish:Kvartsi
French:Quartz
Galician:Cuarzo
Greek:Χαλαζίας
Hebrew:קוורץ
Hungarian:Kvarc
Indonesian:Kuarsa
Irish Gaelic:Grian Cloch
Italian:Quarzo
Korean:석영
Latvian:Kvarcs
Lithuanian:Kvarcas
Luxembourgish:Quarz
Macedonian:Кварц
Malagasy:Vatokaranana
Vatovelona
Vatovelona
Malay:Kuarza
Norwegian:Kvarts
Polish:Kwarc
Portuguese:Quartzo
Romanian:Cuarţ
Russian:Кварц
Serbian:Кварц
Slovak:Kremeň
Slovenian:Kamena strela
Spanish:Cuarzo
Swedish:Kvarts
Thai:ควอตซ์
Traditional Chinese:石英
Turkish:Kuvars
Ukrainian:Кварц
Vietnamese:Thạch anh
Varieties of Quartz
"Herkimer-style" Quartz | This is a collective name to group together the many different local names for transparent, lustrous quartz crystals, usually doubly-terminated, often associated with inclusions of petroleum and/or associated with oil or coal deposits within sedimentary r... |
Agate | A distinctly banded fibrous chalcedony. Originally reported from Dirillo river (Achates river), Acate, Ragusa Province, Sicily, Italy. The banding in agate is based on periodic changes in the translucency of the agate substance. Layers appear darker when... |
Agate-Jasper | A variety of agate consisting of Jasper veined with Chalcedony. |
Agatized coral | A variety of agate/chalcedony replacing coral. |
Alladinite | A name given to a jasper found in Wabuska, Nevada. Also, unrelatedly, a name for a synthetic casein resin and possibly as a marketing name for gem diopside. |
Amarillo Stone | A figured variety of chalcedony. May be the same as Alibates flint. |
Amberine | Yellow to yellow-green chalcedony variety found in Death Valley, Inyo Co., California, USA. |
Amethyst | A violet to purple variety of quartz that owes its color to gamma irradiation (Berthelot, 1906) and the presence of traces of iron built into its crystal lattice (Holden, 1925). The irradiation causes the iron Fe(+3) atoms that replace Si in the lattice t... |
Ametrine | Ametrine crystals are made of alternating sectors of purple and yellow to orange color. Slabs cut perpendicular to the c axis of the crystal look a bit like a pinwheel. The purple sectors are situated under the positive rhombohedral faces (r), and the yel... |
Apricotine | Reddish-yellow waterworn apricot-coloured quartz pebbles. Originally described from Sunset Beach, Cape May, Lower Township, Cape May Co., New Jersey, USA. |
Aquaprase | Aquaprase is a registered trademark of Melas, Ionannis Bloumstrom and Chordia, Avant Kumar who are marketing this material. A bluish green chalcedony, colored by chromium and nickel, is marketed under the trade name “Aquaprase.” Origin is an unspecif... |
Arkansas Candle | A cluster of clear Quartz crystals in a candle-like formation. Also single crystals that show a greater than 7 to 1 length to width ratio. |
Aventurine | A variety of quartz containing glistening fragments (usually mica, such as fuchsite, but also hematite), which can be cut and polished as a gemstone. Most commonly when the general public encounter this stone it is in the form of green stone beads that ca... |
Azurchalcedony | Chalcedony coloured by Chrysocolla, from Arizona, USA |
Babel-Quartz | A historical name given for a variety of quartz named for the fancied resemblance of the crystals to the successive tiers of the Tower of Babel. In some cases, but not all, the morphology is caused by growth inhibition by other minerals (later dissolved... |
Ball Jasper | Jasper showing concentric red and yellow bands. Jasper occurring in spherical masses. |
Bayate | A local name for a brown ferruginous variety of Jasper. Originally described from Oriente Province, Cuba. |
Beekite | A name given to Chalcedony pseudomorphs after coral or shells. Originally described from Devon, England, UK. |
Bergerit | Local name for a net-like jasper. |
Binghamite | Binghamite refers to a diverse group of lapidary materials from the mines on the Cuyuna North Iron Range in Crow Wing County, Minnesota. It is related to Minnesota silkstone and Minnesota tigers' eye. In fact all three materials can be found in the same s... |
Bird's Eye Agate | A variety of eye agate where the eyes are supposed to resemble the eyes of a bird. |
Blue Chalcedony | Blue colour caused by the Tyndall effect (light scattering by colloid sized particles). Transmitted light looks yellowish or reddish rather than blue. |
Blue Lace Agate | A pale blue banded variety of Agate (Chalcedony). |
Blue Quartz | An opaque to translucent, blue variety of quartz, owing its colour to inclusions, commonly of fibrous magnesioriebeckite or crocidolite, or of tourmaline. The color may be caused by the color of the included minerals or by Rayleigh scattering of light at ... |
Botswana Agate | A variety of agate from Botswana, banded with fine, parallel lines, often coloured pink blending into white. |
Brecciated Agate | A naturally cemented matrix of broken agate fragments. |
Buhrstone | A cellular flinty material used for millstones. |
Bull Quartz | Milky to greyish, massive. |
Burnt amethyst | Heated amethyst; the heating results in a yellow-orange, yellow-brown, or dark brownish colour. Often incorrectly sold as citrine. |
Cactus Quartz | Quartz crystals encrusted by a second generation of smaller crystals grown on the prism faces. The small second generation crystals point away from the prism and their orientation is not related to the crystallographic orientation of the central crystal. ... |
Cape May Diamond | Waterworn transparent quartz pebbles. A locally applied marketing name/ploy to clear, colorless quartz beach pebbles occurring along the Delaware Bay beaches of Cape May County, New Jersey, USA. Cut stones from these pebbles are sold in tourist areas of t... |
Capped Quartz | Quartz crystals made of loosely connected or easily separable parts that correspond to different growth phases. This is caused by the deposition of thin continuous layers of, for example, clay minerals, on the crystal during growth. The typical result is ... |
Carnelian | A reddish variety of Chalcedony. |
Catalinite | |
Chalcedony | Depending on the context, the term "chalcedony" has different meanings. 1. A more general term for all varieties of quartz that are made of microscopic or submicroscopic crystals, the so-called microcrystalline varieties of quartz. Examples are the diffe... |
Chrome-Chalcedony | A variety of chalcedony colored deep green by Cr compounds. (Compare with the more common chrysoprase variety of chalcedony, which is colored by nickel.) Chrome chalcedony found in an ancient Roman gem collection may have come from one of the chromium dep... |
Chrysojasper | A variety of jasper colored by chrysocolla. |
Citrine | A yellow to yellow-orange or yellow-green variety of quartz. Quartz colored by inclusions, or coatings, of any kind is not called citrine. Iron-stained quartz should not be mistaken for citrine. A yellow-green citrine crystal with smoky phantoms.A cut ... |
Clear Lake Diamond | Quartz crystals from the Manke Ranch, Lake County, California. |
Cloud Agate | Greyish agate with patches of blurry, foggy inclusions. |
Cotterite | A variety of quartz with "metallic pearly lustre" coating normal quartz crystals. Originally described from Rock Forest, Mallow, Co. Cork, Ireland. |
Crazy Lace Agate | An agate composed of multicoloured twisting and turning bands. |
Creolite | A red-and-white banded jasper. [Webster (1962), Gems 755] Originally reported from California, USA. |
Cubosilicite | Pseudomorphs of Chalcedonly after Fluorite - small blue cubes |
Dallasite | A variety of jasper from Vancouver Island, British Columbia, Canada. |
Damsonite | Trade name for a light violet to dark purple chalcedony from Arizona. |
Darlingite | Local name for a variety of Jasper. A kind of lydian stone. Originally reported from Victoria, Australia. |
Dendritic Agate | Chalcedony containing dendritic inclusions. |
Diackethyst | A local name for translucent wine and amethystine coloured chalcedony pebbles. Originally described from Craig, Montrose, Tayside (Angus), Scotland, UK. |
Dotsero Diamond | Fanciful local name for quartz crystals enclosed in a geologically recent basalt flow. Being incompatible with basaltic lava, the quartz crystals are rounded by reaction with the surrounding lava. Apparently the crystals were detrital, and got picked up b... |
Dragonite | A rounded quartz pebble representing a quartz crystal that has lost its brilliancy and angular form; in gravels, once believed to be a fabulous stone obtained from the head of a flying dragon. |
Egyptian Jasper | A brown variety jasper (brown alternating with black stripes - Egypt) or red (blood-red, flesh red, yellow, brown - found in Baden), originally described from Egypt. |
Eisenkiesel | A quartz that is colored red, orange or brown by hematite inclusions. Translucent to almost opaque. The term "eisenkiesel" is sometimes also used in a wider sense, as a synonym of ferruginous quartz, for any quartz with iron oxides and hydroxide mineral ... |
El Doradoite | Trade name for blue quartz or chalcedony. Originally described from El Dorado Co., California, USA. |
Ema egg | Trade name for a river-tumbled pebble of transparent quartz with a frosted exterior resembling an egg shell, originally collected from rivers in Brazil, with one side sawn flat and polished as a window to view the interior. Pebbles of quartz and other min... |
Enhydro Agate | An agate nodule partly filled with water. |
Eye Agate | Agate with concentric ring pattern, looking like an eye. |
Faden Quartz | "Faden quartz" is the anglicized version of the German "Fadenquarz". "Faden" (pronounced "fah-den") means "thread" and refers to a white line that runs through the crystal. In French, these are called " quartz a âme " Faden quartz forms in fissures in t... |
Fairburn Agate | A unique and rare variety of Fortification Agate from Fairburn, Custer Co., South Dakota, USA. |
Fensterquarz | Literally "window quartz". Skeletal quartz which has rhombohedral faces appearing like windows. |
Ferruginous Quartz | A variety of quartz colored red, brown, or yellow by inclusions of hematite or limonite, and usually massive and opaque. |
Fire Agate | A variety of chalcedony containing inclusions of goethite or limonite, producing an iridescent effect or "fire." |
Fortification Agate | Agate with sharp-angled bands which resemble the outlines of fortifications of a castle. |
Fossil Agate | Agate as a replacement material in fossils. |
Haema-ovoid-agates | Name proposed for a reddish agate with ovoidal patches of cacholong, etc. |
Hair Amethyst | A name for acicular crystals of Amethyst. |
Haytorite | Although the original specimens from Haytor Mine were pseudomorphs of quartz after datolite, the name has been frequently used in Cornwall also for quartz pseudomorphs after a veriety of other minerals, including calcite dolomite and siderite (see e.g. Co... |
Herbeckite | A variety of Agate or Jasper impregnated with Iron Hydrate. [Clark, 1993 - "Hey's Mineral Index"] Originally described from Hrbek Mine, Svatá Dobrotivá (St Benigna), Beroun (Beraun), Central Bohemia Region, Bohemia (Böhmen; Boehmen), Czech Republic. |
Iris Agate | An iridescent variety of agate - when sliced into a thin section it exhibits all the colours of the spectrum when viewed in transmitted light. |
Iris Quartz | Quartz crystals displaying internal spectral colours under minor rhombohedral faces. This interference phenomenon is due to reflection and refraction on extremely thin parallel Brazil-law twinning lamellae or periodic etching of defects on z faces, result... |
Irnimite | Very special multicolor black-blue-brown-white local variety of jasper or microquartzite associated with manganese ores of Taikan range in Eastern Siberia. Its coloration is caused by: black - manganese oxides (very often braunite), blue - alkali amphibol... |
Jacinto de Compostela | In Spanish mineralogical literature, the name is traditionally used exclusively for the red "floater" variety of authigenic quartzes from continental gypsum-bearing marls of the Triassic Keuper formation. (They may also be found occasionally in younger Te... |
Jasper | Geologically the name has long been used for an opaque to slightly translucent, generally red or brown to variably coloured, impure chalcedony or microcrystalline chert, usually containing abundant fine inclusions of hematite, iron hydroxides and other mi... |
Keystonite Chalcedony | A local trade name for Chalcedony coloured blue by Chrysocolla. |
Kinradite | An orbicular jasper originally observed in the San Francisco area and named for lapidary J J Kinrade. See: "Kinradite": Orbicular Jasper from San Francisco |
Laguna Agate | A colourful agate variety. Originally described from Ojo Laguna, Chihuahua, Mexico. |
Lake Superior Agate | Believed to be the world's oldest agates, over 1 billion years old, these are found throughout the northern US having been spread from the original Lake Superior region by glaciation. It has generally pale colouring. |
Landscape Agate | A variety of chalcedony with inclusions giving the appearance of a landscape scene. |
Lithium Quartz | A name in common trade use for a pink/purple translucent to opaque variety of quartz, possibly containing inclusions of a lithium-rich mineral such as lepidolite - however it could equally be a misleading/incorrect name, and should be regarded a simply a ... |
Mexican Lace Agate | Lacy or wavy agate from Mexico. |
Milky Quartz | A semi-transparent to opaque white-coloured variety of quartz. |
Mocha Stone | A variety of agate (chalcedony) containing inclusions of pyrolusite. Originally described from Mocha, Saudi Arabia. |
Moss Agate | A variety of Chalcedony frequently containing green mineral inclusions (eg Chlorite, Hornblende, etc.) or brown to black dendrites of iron or manganese oxides. |
Mutzschen Diamonds | Clear variety of quartz (rock crystal) from Mutzschen, Saxony. Occurs in voids of Permian volcanic rocks (rhyolites). |
Myrickite | Local name for a chalcedony with grey ground and red spots (inclusions of cinnabar). Originally described from Myrick Spring, San Bernardino Co., California, USA. |
Nipomo Agate | Chalcedony with inclusions of Marcasite. Originally described from Nipomo, San Luis Obispo Co., California, USA. |
Oil Quartz | A variety of Quartz from Tyrol, Austria, which contains yellow stains in cracks. BM 1924,110 and 111 are two specimens in the Natural History Museum, London. [Clark, 1993 - "Hey's Mineral Index"] |
Onyx | In correct usage, the name refers to a (usually) black and white banded variety of agate, or sometimes a monochromatic agate with dark and light parallel bands (brown and white for example) - but traditionally the name was reserved for black and white ban... |
Owyhee Jasper | |
Pastelite | Variety of jasper exhibiting pastel colors. |
Pecos Diamonds | Colourful, doubly-terminated quartz crystals that occur in the Permian Seven Rivers Formation along the Pecos River valley in southeastern New Mexico. |
Phantomquarz | A variety of quartz that shows one or more phantoms. (See phantom crystal). |
Pietersite | Chalcedony with embedded fibers of amphibole minerals with varying degrees of alteration. Blue-gray, brown and yellow colors. The fibers cause a chatoyancy similar to that seen in tiger's eye, but tiger's eye is not made of chalcedony, it is macrocrystall... |
Pigeon Blood Agate | A blood-red and white variety of agate from Utah. |
Plasma | A microgranular or microfibrous form of chalcedony coloured in various shades of green by disseminated silicate particles (variously attributed to celadonite, chlorite, amphibole, etc.). Various descriptions of Plasma include of a dullish green color wi... |
Plume Agate | A variety of chalcedony with contrasting colored, plume-like structures within the material. Compare with moss agate. |
Prase | Originally, the varietal name "prase" was applied to a dull leek-green colored quartzite (a rock, not a mineral*); but over the years it has been also applied to other materials, particularly a green colored jasper of similar color. For perhaps more than... |
Prase-malachite | A term for Prase enclosing Malachite. |
Prasiolite | A green transparent variety of macrocrystalline quartz. Compare with prase and plasma. Not to be confused with prasolite! |
Pseudocubic Quartz | Crystals with a (pseudo)cubic appearance that are dominated by a single rhombohedral form (usually r, { 1 0 -1 1 }). Since the angles of the rhombohedron differ only very little from that of a perfect cube (85.2° and 94.8°, respectively, instead of 90°... |
Quartz Gwindel | Quartz crystals that grew along and are slightly rotated around a single a-axis. This results in twisted and tabular crystals. The twist reflects the handedness of the quartz crystals. With increasing distance from the base - right-handed gwindels twist c... |
Quartzine | Quartzine is a fibrous variety of chalcedony. It is also called "length-slow chalcedony" and is usually intergrown with another, more common type of fibrous chalcedony, "length-fast chalcedony", that comprises most of the different varieties of chalcedony... |
Quetzalitztli | Translucent, emerald green jasper from Guatemala, colored by inclusions of Cr-muscovite. |
Riband Agate | According to Hey's 3rd Ed. this is 'a banded agate', which doesn't tell us much! |
Riband Jasper | A banded Jasper |
Rock Crystal | A transparent colourless variety of quartz. |
Rose Quartz | Two varieties of quartz are commonly called "rose quartz". 1. One is found in translucent masses made of intergrown anhedral crystals. It occurs in different hues of pink, sometimes bluish, sometimes more reddish; irradiation may cause the formation of ... |
Rutilated Quartz | Quartz shot through with needles of Rutile. |
Sagenite (of Kunz) | A redefinition by Kunz in 1892 (possibly a misunderstanding) of the original name Sagenite as defined by Saussure to refer to a variety of quartz - see also Sagenite (of Saussure) and Rutilated Quartz - a more common modern name to refer to Quartz contain... |
Sard | A brown to brownish-red translucent variety of chalcedony. Pliny the Elder stated that it was named after Sardis, in Lydia, where it was first discovered; but the name probably came with the stone from Persia (Persian sered = yellowish-red). |
Sardonyx | A variety of Agate with reddish-brown and either black or white bands. |
Sceptre Quartz | Sceptre quartzes (American English spelling: Scepter quartzes) are crystals in which a second generation crystal tip grew on top of another quartz crystal. In a typical scepter quartz, the younger tip is larger than the first tip, but it may also be small... |
Schwimmstein | Earthy quartz, as nodular to mamillary masses, as coating on flint. Specific weight < 1, therefore floating on water. |
Seftonite | A translucent, moss green variety of chalcedony. |
Shocked Quartz | Quartz shocked under intense pressure (but limited temperature). During the pressure shock, the crystalline structure of quartz will be deformed along planes inside the crystal. These planes, which show up as lines under a microscope, are called planar de... |
Smoky Quartz | A smoky-gray, brown to black variety of quartz that owes its color to gamma irradiation and the presence of traces of aluminum built into its crystal lattice (Griffiths et al, 1954; O'Brien, 1955). The irradiation causes the aluminum Al(+3) atoms that rep... |
Snakeskin Agate | Chalcedony with snakeskin-like surface pattern. |
Star Quartz | Refers to the shape of an aggregate of radiating crystals; not to be confused with the optical property "asterism". Star quartz usually grows at low temperature, often around a core of chalcedony. |
Suttroper Quarz | Name used for biterminated, milky quartz crystals originally described from Suttrop, Warstein, Sauerland, North Rhine-Westphalia, Germany. Generally used in the plural form, 'Suttroper Quarze', or more correctly (because Suttrop is not the only locality),... |
Vogelaugenjaspis | |
Watercolour jasper | Very special multicolor black-blue-brown-white local variety of Jasper or microquartzite associated with manganese ores of Taikan range in Eastern Siberia. |
Wilkite | A yellow, purple, pink, and green jasper from Willow Creek, Ada County, Idaho, USA. |
Youngite | Local name for agate or jasper coated by druzy quartz crystals. Found near Guernsey, Platte Co., Wyoming, USA, in limestone rocks. |
Common Associates
Associated Minerals Based on Photo Data:
12,833 photos of Quartz associated with Fluorite | CaF2 |
11,848 photos of Quartz associated with Calcite | CaCO3 |
9,409 photos of Quartz associated with Pyrite | FeS2 |
7,208 photos of Quartz associated with Sphalerite | ZnS |
5,261 photos of Quartz associated with Chalcopyrite | CuFeS2 |
4,935 photos of Quartz associated with Galena | PbS |
4,498 photos of Quartz associated with Hematite | Fe2O3 |
4,423 photos of Quartz associated with Siderite | FeCO3 |
4,145 photos of Quartz associated with Dolomite | CaMg(CO3)2 |
3,407 photos of Quartz associated with Rhodochrosite | MnCO3 |
Related Minerals - Strunz-mindat Grouping
4.DA. | Chibaite | SiO2 · n(CH4, C2H6, C3H8, i-C4H10) (n = 3/17 (max)) | Iso. m3 (2/m 3) : Fd3 |
4.DA. | Carbon Dioxide Ice | CO2 | |
4.DA. | Bosoite | SiO2 · nCxH2x+2 | Hex. 6/mmm (6/m 2/m 2/m) : P6/mmm |
4.DA.10 | Opal | SiO2 · nH2O | |
4.DA.10 | Tridymite | SiO2 | Tric. 1 |
4.DA.15 | Cristobalite | SiO2 | Tet. 4 2 2 : P41 21 2 |
4.DA.20 | Mogánite | SiO2 | Mon. |
4.DA.25 | Melanophlogite | 46SiO2 · 6(N2,CO2) · 2(CH4,N2) | Tet. 4/mmm (4/m 2/m 2/m) |
4.DA.30 | Lechatelierite | SiO2 | Amor. |
4.DA.35 | Coesite | SiO2 | Mon. 2/m : B2/b |
4.DA.40 | Stishovite | SiO2 | Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm |
4.DA.45 | Keatite | SiO2 | Tet. 4 2 2 : P43 21 2 |
4.DA.50 | Seifertite | SiO2 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
4.DA.55 | Quartz-beta | SiO2 | Hex. 6 2 2 : P64 2 2 |
Other Information
Electrical:
piezoelectric, pyroelectric, may be triboluminescent.
Thermal Behaviour:
Transforms to beta-quartz at 573° C and 1 bar (100 kPa) pressure.
Health Risks:
Quartz is usually quite harmless unless broken or powdered. Broken crystals and masses may have razor-sharp edges that can easily cut skin and flesh. Handle with care. Do not grind dry since long-term exposure to finely ground powder may lead to silicosis.
Industrial Uses:
Ore for silicon, glassmaking, frequency standards, optical instruments, silica source for concrete setting, filtering agents as sand. A major component of sand.
Quartz in petrology
An essential component of rock names highlighted in red, an accessory component in rock names highlighted in green.
- Igneous rock
- Normal crystalline igneous rock
- Exotic crystalline igneous rock
- Pegmatite
- Sedimentary rock and sediment
- Metamorphic rock
- Pyrometamorphic rock
- Queluzite
- Meta-igneous rock
- Metasedimentary rock
- High-grade metamorphic rock
- Very low to low-grade metamorphic rock
- Gneiss
- Granofels
- Schist
- Metasomatic-rock
- Epidosite
- Unclassified rock
References for Quartz
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Rülein von Calw, U. (1527) Querz. in: Ein nützlich Bergbüchlin: von allen Metallen / als Golt / Silber / Zcyn / Kupferertz / Eisenstein / Bleyertz / und vom Quecksilber, Loersfelt (Erffurd) 25, 38.
Agricola, G. (1530) Quarzum. in: Bermannus, Sive De Re Metallica, in aedibus Frobenianis (Basileae) 88, 129.
Agricola, G. (1546) Book V. Quartz. in: De Natura Fossilium, Froben (Basileae) 249-275.
Bras-de-Fer, L. (1778) (84) Terre (Élément). in: Explication Morale du Jeu de Cartes; Anecdote Curieuse et Interessante, (Bruxelles), 99-100.
Hoffmann, C.A.S. (1789) Mineralsystem des Herrn Inspektor Werners mit dessen Erlaubnis herausgegeben von C.A.S. Hoffmann. Bergmännisches Journal: 1: 369-398.
Berzelius, J.J. (1810) Zerlegung der Kieselerde durch gewöhnliche chemische Mittel. Annalen der Physik: 36: 89-102. [Discovery of silicon, quartz being made of silicon and oxygen]
Arago, F.J.D. (1811) Mémoire sur une modification remarquable qu'éprouvent les rayons lumineux dans leur passage à travers certains corps diaphanes et sur quelques autres nouveaux phénomènes d'optique. Mémoires de la classe des sciences mathématiques et physiques de l'Institut Impérial de France Année 1811. 1re partie: 92-134. [discovery of optical activity of quartz and of interference colors in polarized light]
Biot, J.B. (1812) Mémoire sur une nouveau genre d'oscillation, que les molecules de la lumiére éprouvent en traversant certains cristeaux. Mémoires de la classe des sciences mathématiques et physiques de l'Institut Impérial de France Année 1812. 1re partie: 1-371.
Weiss, C.S. (1816) Ueber den eigenthümlichen Gang des Krystallisations-systemes beim Quarz, und über eine an ihm neu beobachtete Zwillingskrystallisation. Mitteilungen der Gesellschaft Naturforschender Freunde, Berlin: 7: 163-181. [first description of Dauphiné twin law]
Herschel, J.F.W. (1822) On the rotation impressed by plates of rock crystal on the planes of polarization of the rays of light, as connected with certain peculiarities in its crystallization. Transactions of the Cambridge Philosophical Society: 1: 43-51.
Brewster, D. (1823) On circular polarization, as exhibited in the optical structure of the amethyst, with remarks on the distribution of the colouring matter in that mineral. Transactions of the Royal Society of Edinburgh: 9: 139-152.
Weiss, C.S. (1829) Über die herzförmig genannten Zwillingskrystalle von Kalkspath, und gewisse analoge von Quarz. Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin: 77-87.
Leydolt, F. (1855) Über eine neue Methode, die Structur und Zusammensetzung der Krystalle zu untersuchen, mit besonderer Berücksichtigung der Varietäten des rhomboedrischen Quarzes. Sitzungsberichte der mathematisch naturwissenschaftlichen Classe der kaiserlichen Akademie der Wissenschaften: 15: 59-81.
Rammelsberg, C. (1861) Ueber das Verhalten der aus Kieselsäure bestehenden Mineralien gegen Kalilauge. Annalen der Physik und Chemie: 112: 177-192.
Jenzsch, G. (1867) Ueber die am Quarze vorkommenden sechs Gesetze regelmäßiger Verwachsung mit gekreuzten Hauptaxen. Annalen der Physik: 206: 597-611.
Jenzsch, G. (1868) Ueber die Gesetze regelmäßiger Verwachsung mit gekreuzten Hauptaxen am Quarze. Annalen der Physik: 210: 540-551.
Firket, A. (1878) Sur une variété de quartz pulvérulent. Annales de la Société géologique de Belgique, 5, XC.
Judd, J.W. (1888) On the development of a lamellar structure in quartz-crystals by mechanical means. The Mineralogical Magazine and Journal of the Mineralogical Society: 8: 1-10.
Meyer, T. (1888) Action of hydrofluoric acid on a sphere of quartz. Proceedings of the Natural Academy of Sciences of Philadelphia: 40: 121.
Cesàro, G. (1890) Notes sur les figures de corrosion du quartz par l'acide fluorhydrique. Annales de la Société géologique de Belgique, 17, LV.
Abraham, A. (1913) Quartz fibreux. Annales de la Société géologique de Belgique, 40, B275.
Fenner, C.N. (1913) The stability relations of the silica minerals. American Journal of Sciences: 36: 331-384.
Zyndel, F. (1913) Über Quarzzwillinge mit nichtparallelen Hauptaxen. Zeitschrift für Krystallographie: 53(1): 15-52.
Adams, S. (1920) A microscopic study of vein quartz. Economic Geology: 15: 623-664.
Weber, L. (1922) Beobachtungen an schweizerischen Bergkristallen. Schweizerische mineralogische und petrographische Mitteilungen: 2: 276-282.
Bragg, W., Gibbs, R.E. (1925) The structure of α and β quartz. Proceedings of the Royal Society of London, Series A: 109(751) 405-427.
Gibbs, R.E. (1926) Structure of α quartz. Proceedings of the Royal Society of London, Series A: 110(754) 443-455.
Hart, G. (1927) The nomenclature of silica. American Mineralogist: 12: 383-395.
Sosman, R.B. (1927) The properties of silica. American Chemical Society, Monograph No.37, 856pp.
Gibson, R.E. (1928) The influence of pressure on the high-low inversion of quartz. Journal of Physical Chemistry: 32: 1197-1205.
Tarr, W.A., Lonsdale, J.T. (1929) Pseudo-cubic quartz crystals from Artesia, New Mexico. American Mineralogist: 14: 50-53.
Tolman, C. (1931) Quartz dikes. American Mineralogist: 16: 278-299.
Weil, R. (1931) Quelques observations concernant la structure du quartz. Compte Rendu 1er Réunion de l'Institut d'Optique: 2-11.
Schubnikow, A., Zinserling, K. (1932) Über die Schlag- und Druckfiguren und über die mechanischen Quarzzwillinge. Zeitschrift für Kristallographie: 74: 243-264.
Drugman, J. (1939) Prismatic cleavage and steep rhombohedral form in α-quartz. Mineralogical Magazine: 25: 259-263.
Koenigsberger, J.G. (1940) Die zentralalpinen Minerallagerstätten. Teil III. Wepf & Co. Verlag, Basel.
Raman, C.V., Nedungadi, T.M.K. (1940) The α-β transition of quartz. Nature: 145: 147.
Tomkeieff, S.I. (1941) Origin of the Name 'Quartz'. Mineralogical Magazine: 26: 172-178.
Frondel, C. (1945) History of the quartz oscillator-plate industry, 1941-1944. American Mineralogist: 30: 205-213.
Frondel, C. (1945) Secondary Dauphiné twinning in quartz. American Mineralogist: 30: 447-460.
Krishnan, R.S. (1945) Raman spectrum of quartz. Nature: 155: 452.
Thomas, L.A. (1945) Terminology of interpenetrating twins in α-quartz. Nature: 155: 424.
Armstrong, E. (1946) Relation between secondary Dauphiné twinning and irradiation-coloring in quartz. American Mineralogist: 31: 456-461.
Baker, G. (1946) Microscopic quartz crystals in brown coal, Victoria. American Mineralogist: 31: 22-30.
Friedman, I.I. (1947) The laboratory growth of quartz. American Mineralogist: 32: 583-588.
Faust, G.T. (1948) Thermal analysis of quartz and its use in calibration in thermal analysis studies. American Mineralogist: 33: 337-345.
Gault, H.R. (1949) The frequency of twin types in quartz crystals. American Mineralogist: 34: 142-162.
Tuttle, O.F. (1949) The variable inversion temperature of quartz as a possible geologic thermometer. American Mineralogist: 34: 723-730.
Chapman, C.A. (1950) Quartz veins formed by metamorphic differentiation of aluminous schists. American Mineralogist: 35: 693-710.
Friedlaender, C. (1951) Untersuchung über die Eignung alpiner Quarze für piezoelektrische Zwecke. Beiträge zur Geologie der Schweiz, Geotechnische Serie, Lieferung 29.
Brown, C.S., Kell, R.C., Thomas, L.A., Wooster, N., Wooster, W.A. (1952) Growth and properties of large crystals of synthetic quartz. Mineralogical Magazine: 29: 858-874.
Kozu, S. (1952) Japanese twins of quartz. American Journal of Science: Bowen Volume Part 1: 281-292.
Van Praagh, G., Willis, B.T.M. (1952) Striations on prism faces of quartz. Nature: 169: 623-624.
Fairbairn, H.W. (1954) The stress-sensitivity of quartz in tectonites. Tschermaks mineralogische und petrographische Mitteilungen: 4: 75-80.
Frederickson, A.F., Cox, J.E. (1954) Mechanism of "solution" of quartz in pure water at elevated temperatures and pressures. American Mineralogist: 39: 886-900.
Frederickson, A.F. (1955) Mosaic structure in quartz. American Mineralogist: 40: 1-9.
O'Brien, M.C.M. (1955) The structure of the colour centres in smoky quartz. Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences: 231: 404-414.
Seifert, H. (1955) Über orientierte Abscheidungen von Aminosäuren auf Quarz. Die Naturwissenschaften: 42: 13. [epitaxy of amino acids]
Borg, I. (1956) Note on twinning and pseudo-twinning in detrital quartz grains. American Mineralogist: 41: 792-796.
Krauskopf, K.B. (1956) Dissolution and precipitation of silica at low temperatures. Geochimica et Cosmochimica Acta: 10: 1-26.
de Vries, A. (1958) Determination of the absolute configuration of α-quartz. Nature: 181: 1193.
Dapples, E.C. (1959) The behavior of silica in diagenesis. in: Ireland, H.A. (editor) Silica in Sediments. A symposium sponsored by the Society of Economic Paleontologists and Mineralogists Society of Economic Paleontologists and Mineralogists, Special Publication No.7: 36-54.
Denning, R.M., Conrad, M.A. (1959) Directional grinding hardness of quartz by peripheral grinding. American Mineralogist: 44: 423-428.
Krauskopf, K.B. (1959) The geochemistry of silica in sedimentary environments. in: Ireland, H.A. (editor) Silica in Sediments. A symposium sponsored by the Society of Economic Paleontologists and Mineralogists Society of Economic Paleontologists and Mineralogists, Special Publication No.7: 4-19.
Foster, R.J. (1960) Origin of embayed quartz crystals in acidic volcanic rocks. American Mineralogist: 45: 892-894.
Ballman, A.A. (1961) Growth and properties of colored quartz. American Mineralogist: 46: 439-446.
Bambauer, H.U. (1961) Spurenelementgehalte und -Farbzentren in Quarzen aus Zerrklüften der Schweizer Alpen. Schweizerische mineralogische und petrographische Mitteilungen: 41: 335-369.
Bambauer, H.U., Brunner, G.O., Laves, F. (1961) Beobachtungen über Lamellenbau an Bergkristallen. Zeitschrift für Kristallographie: 116: 173-181.
Bambauer, H.U., Brunner, G.O., Laves, F. (1962) Wasserstoff-Gehalte in Quarzen aus Zerrklüften der Schweizer Alpen und die Deutung ihrer regionalen Abhängigkeit. Schweizerische mineralogische und petrographische Mitteilungen: 42: 221-236.
Brace, W.F., Walsh, J.B. (1962) Some direct measurements of the surface energy of quartz and orthoclase. American Mineralogist: 47: 1111-1122.
Frondel, C. (1962) Dana's System of Mineralogy, 7th Edition: Vol. III: Silica Minerals. John Wiley, New York and London.
Bambauer, H.U., Brunner, G.O., Laves, F. (1963) Merkmale des OH-Spektrums alpiner Quarze (3μ-Gebiet). Schweizerische mineralogische und petrographische Mitteilungen: 43: 259-268.
Blatt, H., Christie, J.M. (1963) Undulatory extinction in quartz of igneous and metamorphic rocks and its significance in provenance studies of sedimentary rocks. Journal of Sedimentary Research: 33: 559-579.
Bloss, F.D., Gibbs, G.V. (1963) Cleavage in quartz. American Mineralogist: 48: 821-838.
Gansser, A. (1963) Quarzkristalle aus den kolumbianischen Anden (Südamerika). Schweizerische mineralogische und petrographische Mitteilungen: 43: 91-103.
Lang, A.R. (1965) Mapping Dauphiné and Brazil twins in quartz by X-ray topography. Applied Physics Letters: 7: 168-170.
Dennen, W.H. (1966) Stoichiometric substitution in natural quartz. Geochichimica et Cosmochimica Acta: 30: 1235-1241.
Lehmann, G., Moore, W.J. (1966) Color center in amethyst quartz. Science: 152: 1061-1062.
McLaren, A.C., Retchford, J.A., Griggs, D.T., Christie, J.M. (1967) Transmission electron microscope study of Brazil twins and dislocations experimentally produced in natural quartz. Physica Status Solidi: 19: 631-645.
Carr, R.M. (1968) The problem of quartz-corundum stability. American Mineralogist: 53: 2092-2095.
Carstens, H. (1968) A note on the origin of Brazil twins in lamellar quartz. Norsk Geologiske Tidsskrift: 48: 61-64.
Carstens, H. (1968) The lineage structure of quartz crystals. Contributions to Mineralogy and Petrology: 18: 295-304.
Frondel, C. (1968) Quartz twin on {3032}. Mineralogical Magazine: 36: 861-864.
Bambauer, H.U., Brunner, G.O., Laves, F. (1969) Light scattering of heat-treated quartz in relation to hydrogen-containing defects. American Mineralogist: 54: 718-724.
Kushiro, I. (1969) The system forsterite-diopside-silica with and without water at high pressures. American Journal of Science: 267: 269-294.
McLaren, A.C., Phakey, P.P. (1969) Diffraction contrast from Dauphiné twin boundaries in quartz. Physica Status Solidi: 31: 723-737.
Rice, S.J. (1969) Quartz family minerals. California Division of Mines and Geology Mineral Information Service: 22: 35-38.
Carmichael, I.S.E., Nicholls, J., Smith, A.I. (1970) Silica activity in igneous rocks. American Mineralogist: 55: 246-263.
Feigl, F.J., Anderson, J.H. (1970) Defects in crystalline quartz: electron paramagnetic resonance of E' vacancy centers associated with germanium impurities. Journal of Physics and Chemistry of Solids: 31: 575-596.
Calvert, S.E. (1971) Nature of silica phases in deep sea cherts of the North Atlantic Ocean. Nature Physical Science: 234: 133-134.
Mackenzie, F.T., Gees, R. (1971) Quartz: Synthesis at earth-surface conditions. Science: 173: 533-535.
Scott, S.D., O'Connor, T.P. (1971) Fluid inclusions in vein quartz, Silverfields Mine, Cobalt, Ontario. The Canadian Mineralogist 11, 263-271.
Bates, J.B., Quist, A.S. (1972) Polarized Raman spectra of β-quartz. The Journal of Chemical Physics: 56: 1528-1533.
Baëta, R.D., Ashbee, K.H.G. (1973) Transmission electron microscopy studies of plastically deformed quartz. Physica Status Solidi A: 18: 155-170.
Gross, G. (1973) Trigonale Symmetrie anzeigende Querstreifung bei Bergkristall. Schweizerische Mineralogische und Petrographische Mitteilungen: 53: 173-183.
Bettermann, P., Liebau, F. (1975) The transformation of amorphous silica to crystalline silica under hydrothermal conditions. Contributions to Mineralogy and Petrology: 53: 25-36.
Donnay, J.D.H., Le Page, Y. (1975) Twin laws versus electrical and optical characters in low quartz. The Canadian Mineralogist: 13: 83-85.
Barron, T.H.K, Huang, C.C., Pasternak, A. (1976) Interatomic forces and lattice dynamics of α-quartz. Journal of Physics C: Solid State Physics: 9: 3925-3940.
Chakraborty, D., Lehmann, G. (1976) Distribution of OH in synthetic and natural quartz crystals. Journal of Solid State Chemistry: 17: 305-311.
Chakraborty, D., Lehmann, G. (1976) On the structures and orientations of hydrogen defects in natural and synthetic quartz crystals. Physica Status Solidi A: 34: 467-474.
Le Page, Y., Donnay, G. (1976) Refinement of the crystal structure of low-quartz. Acta Crystallographica: B32: 2456-2459.
Van Goethem, L., Van Landuyt, J., Amelinckx, S. (1977) The α-β transition in amethyst quartz as studied by electron microscopy and diffraction. The interaction of Dauphiné with Brazil twins. Physica Status Solidi: 41: 129-137.
Flick, H., Weissenbach, N. (1978) Magmatische Würfelquarze in Rhyolithen (Quarzkeratophyren) des Rheinischen Schiefergebirges. Tschermaks Mineralogische und Petrographische Mitteilungen: 25: 117-129.
Donnay, J. D. H. and Le Page, Y. (1978): The vicissitudes of the low-quartz crystal setting or the pitfalls of enantiomorphism. Acta Crystallogr. A34, 584-594.
Robin, P.Y.F. (1979) Theory of metamorphic segregation and related processes. Geochimica et Cosmochimica Acta: 43(10): 1587-1600.
Maschmeyer, D., Niemann, K., Hake, K., Lehmann, G., Räuber, A. (1980) Two modified smoky quartz centres in natural citrine. Physics and Chemistry of Minerals: 6: 145-156.
Flörke, O.W., Mielke, H.G., Weichert, J., Kulke, H. (1981) Quartz with rhombohedral cleavage from Madagascar. American Mineralogist: 66: 596-600.
Sprunt, E.S. (1981) Causes of quartz cathodoluminescence colours. Scanning Electron Microscopy: 525-535.
Wright, A.F., Lehmann, M.S. (1981) The structure of quartz at 25 and 590°C determined by neutron diffraction. Journal of Solid State Chemistry: 36: 371-380.
Bohlen, S.R., Boettcher, A.L. (1982) The quartz-coesite transformation: a precise determination and the effects of other components. Journal of Geophysical Research: 87(B8): 7073-7078.
McLaren, A.C., Pitkethly, D.R. (1982) The twinning microstructure and growth of amethyst quartz. Physics and Chemistry of Minerals: 8: 128-135.
Richet, P., Bottinga, Y., Deniélou, L., Petitet, J.P., Téqui, C. (1982) Thermodynamic properties of quartz, cristobalite, and amorphous SiO2: drop calorimetry measurements between 1000 and 1800 K and a review from 0 to 2000 K. Geochimica et Cosmochimica Acta: 46: 2639-2658.
Serebrennikov, A.J., Valter, A.A., Mashkovtsev, R.I., Scherbakova, M.Ya. (1982) The investigation of defects in shock-metamorphosed quartz. Physics and Chemistry of Minerals: 8: 155-157.
Yasuda, T., Sunagawa, I. (1982) X-ray topographic study of quartz crystals twinned according to japan twin law. Physics and Chemistry of Minerals: 8(3): 121-127.
Maschmeyer, D., Lehmann, G. (1983) A trapped-hole center causing rose coloration of natural quartz. Zeitschrift für Kristallographie: 163: 181-186.
Scandale, E., Stasi, F., Zarka, A. (1983) Growth defects in a Quartz Druse. ac Dislocations. Journal of Applied Crystallography: 16: 39-403.
Sunagawa, I., Yasuda, T. (1983) Apparent re-entrant corner effect upon the morphologies of twinned crystals; a case study of quartz twinned according to Japanese twin law. Journal of Crystal Growth: 65: 43-49.
Barker, C., Robinson, S.J. (1984) Thermal release of water from natural quartz. American Mineralogist: 69: 1078-1081.
Bernhardt, H.-J., Alter, U. (1984) Induced growth striations in quartz crystals. Crystal Research Technology: 19: 453-460.
Rykart, R. (1984) Authigene Quarz-Kristalle. Lapis Mineralien Magazin: 9(6).
Weil, J.A. (1984) A review of electron spin resonance and its applications to the study of paramagnetic defects in crystalline quartz. Physics and Chemistry of Minerals: 10: 149-165.
Scandale, E., Stasi, F. (1985) Growth defects in Quartz Druses. a Pseudo-basal Dislocations. Journal of Applied Crystallography: 18: 275-278.
Bernhardt, H.-J. (1986) A pragmatic model for the simulation of self-induced striations in quartz crystals. Crystal Research Technology: 21: 983-994.
Sawyer, E.W., Robin, P.-Y.F. (1986) The subsolidus segregation of layer-parallel quartz-feldspar veins in greenschist to upper amphibolite facies metasediments. Journal of Metamorphic Geology: 4: 237-260.
Applin, K.R., Hicks, B.D. (1987) Fibers of dumortierite in quartz. American Mineralogist: 72: 170-172.
Hemingway, B.S. (1987) Quartz: Heat capacities from 340 to 1000 K and revised values for the thermodynamic properties. American Mineralogist: 72: 273-279.
Hurai, V., Stresko, V. (1987) Correlation between quartz crystal morphology and composition of fluid inclusions as inferred from fissures in Central Slovakia (Czechoslovakia). Chemical Geology: 61: 225-239.
Jayaraman, A., Wood, D.L., Maines, R.G. (1987) High-pressure Raman study of the vibrational modes in AlPO4 and SiO2 (α-quartz). Physical Review B: 35: 8316-8321.
Molenaar, N., de Jong, A.F.M. (1987) Authigenic quartz and albite in Devonian limestones: origin and significance. Sedimentology: 34: 623-640.
Ruppert, L.F. (1987) Applications of cathodoluminescence of quartz and feldspar to sedimentary petrology. Scanning Microscopy, 1(1), 63-72.
Graziani, G., Lucchesi, S., Scandale, E. (1988) Growth defects and genetic medium of a quartz druse from Traversella, Italy. Neues Jahrbuch für Mineralogie, Abhandlungen: 159: 165-179.
Owen, M.R. (1988) Radiation-damage halos in quartz. Geology: 16: 529-532.
Ramseyer, K., Baumann, J., Matter, A., Mullis, J. (1988) Cathodoluminescence colours of α-quartz. Mineralogical Magazine: 52: 669-677.
Sowa, H. (1988) The oxygen packings of low-quartz and ReO3 under high pressure. Zeitschrift für Kristallographie: 184: 257-268.
Davidson, P.M., Lindsley, D.H. (1989) Thermodynamic analysis of pyroxene-olivine-quartz equilibria in the system CaO-MgO-FeO-SiO2. American Mineralogist: 74: 18-30.
Drees, L.R., Wilding, L.P., Smeck, N.E., Senkayi, A.L. (1989) Silica in soils: quartz and disordered silica polymorphs. in Minerals in Soil Environments, Editor S.B. Weed. Soil Science Society of America (Madison Wisconsin, USA) 913-974.
Dubrovinskii, L.S., Nozik, Y.Z. (1989) Calculation of the anisotropic thermal parameters of the atoms of α-quartz. Soviet Physics - Doklady: 34: 484-485.
Hazen, R.M., Finger, L.W., Hemley, R.J., Mao, H.K. (1989) High-pressure crystal chemistry and amorphization of α-quartz. Solid State Communications: 72: 507-511.
Scandale, E., Stasi, F., Lucchesi, S., Graziani, G. (1989) Growth marks and genetic conditions in a quartz druse. Neues Jahrbuch für Mineralogie, Abhandlungen: 160: 181-192.
Rao, P.S., Weil, J.A., Williams, J.A.S. (1989) EPR investigation of carbonaceous natural quartz single crystals. The Canadian Mineralogist: 27: 219-224.
Blum, A.E., Yund, R.A., Lasaga, A.C. (1990) The effect of dislocation density on the dissolution rate of quartz. Geochimica et Cosmochimica Acta: 54: 283-297.
Brady, P.V., Walther, J.V. (1990) Kinetics of quartz dissolution at low temperature. Chemical Geology: 82: 253-264.
Dove, P.M., Crerar, D.A. (1990) Kinetics of quartz dissolution in electrolyte solutions using a hydrothermal mixed flow reactor. Geochimica et Cosmochimica Acta: 54: 955-969.
Kihara, K. (1990) An X-ray study of the temperature dependence of the quartz structure. European Journal of Mineralogy: 2: 63-77.
Ribet, I., Thiry, M. (1990) Quartz growth in limestone: example from water-table silicification in the Paris Basin. Geochemistry of the Earth's Surface and Mineral Formation. 2nd International Symposium, July 2, 1990, Aix en Provance, France. Chemical Geology: 84: 316-319.
Taijing, L., Sunagawa, I. (1990) Structure of Brazil twin boundaries in amethyst showing brewster fringes. Physics and Chemistry of Minerals: 17: 207-211.
Chernosky, J.V., Berman, R.G. (1991) Experimental reversal of the equilibrium andalusite + calcite + quartz = anorthite + CO2. The Canadian Mineralogist: 29: 791-802.
Cordier, P., Doukhan, J.C. (1991) Water speciation in quartz: A near infrared study. American Mineralogist: 76: 361-369.
Heaney, P.J., Veblen, D.R. (1991) Observations of the alpha-beta phase transition in quartz: A review of imaging and diffraction studies and some new results. American Mineralogist: 76: 1018-1032.
Lüttge, A., Metz, P. (1991) Mechanism and kinetics of the reaction 1 dolomite + 2 quartz = 1 diopside + 2 CO2 investigated by powder experiments. The Canadian Mineralogist: 29: 803-821.
Agrosì, G., Lattanzi, P., Ruggieri, G., Scandale, E. (1992) Growth history of a quartz crystal from growth marks and fluid inclusions data. Neues Jahrbuch für Mineralogie, Monatshefte: 7: 289-294.
Glinnemann, J., King, H.E., Schulz, H., Hahn, T., La Placa, S.J., Dacol, F. (1992) Crystal structures of the low-temperature quartz-type phases of SiO2 and GeO2 at elevated pressure. Zeitschrift für Kristallographie: 198: 177-212.
Lentz, D.R., Fowler, A.D. (1992) A dynamic model for graphic quartz-feldspar intergrowths in granitic pegmatites in the southwestern Grenville Province. The Canadian Mineralogist: 30: 571-585.
Peucker-Ehrenbrink, B., Behr, H.-J. (1993) Chemistry of hydrothermal quartz in the post-Variscan "Bavarian Pfahl" system, F.R. Germany. Chemical Geology: 103: 85-102.
Rink, W.J., Rendell, H., Marseglia, E.A., Luff, B.J., Townsend, P.D. (1993) Thermoluminescence spectra of igneous quartz and hydrothermal vein quartz. Physics and Chemistry of Minerals: 20: 353-361.
Berti G.(1994) Microcrystalline properties of quartz by means of XRPD measures. Adv. X-Ray Analysis: 37:359-366.
Cohen, R.E. (1994) First-principles theory of crystalline SiO2. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 369-402.
Cordier, P., Weil, J.A., Howarth, D.F., Doukhan, J.C. (1994) Influence of the (4H)Si defect on dislocation motion in crystalline quartz. European Journal of Mineralogy: 6: 17-22.
Dolino, G., Vallade, M. (1994) Lattice dynamical behavior of anhydrous silica. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 403-431.
Dove, P.M., Rimstidt, J.D. (1994) Silica-water interactions. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 259-308.
Gibbs, G.V., Downs, J.W., Boisen, M.B. Jr. (1994) The elusive SiO bond. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 331-368.
Goldsmith, D.F. (1994) Health effects of silica dust exposure. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 545-606.
Graetsch, H. (1994) Structural characteristics of opaline and microcrystalline silica minerals. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 209-232.
Heaney, P.J. (1994) Structure and chemistry of the low-pressure silica polymorphs. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 1-40.
Hemley, R.J., Prewitt, C.T., Kingma, K.J. (1994) High-pressure behavior of silica. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 41-81.
Knauth, L.P. (1994) Petrogenesis of chert. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 233-258.
Kronenberg, A.K. (1994) Hydrogen speciation and chemical weakening of quartz. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 123-176.
Langenhorst, F. (1994) Shock experiments on pre-heated α- and β-quartz: II. X-ray and TEM investigations. Earth and Planetary Science Letters: 128: 683-698.
Navrotsky, A. (1994) Thermochemistry of crystalline and amorphous silica. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 309-329
Rossman, G.R. (1994) Colored varieties of the silica minerals. in: Heaney, P.J., Gibbs, G.V., editors. Reviews in Mineralogy Volume 29 Silica - Physical behaviour, geochemistry and materials applications. Mineralogical Society of America, 433-467.
Swamy, V., Saxena, S.K., Sundman, B., Zhang, J. (1994) A thermodynamic assessment of silica phase diagram. Journal of Geophysical Research 99, 11787-11794.
Dong, G., Morrison, G., Jaireth, S. (1995) Quartz textures in epithermal veins, Queensland - classification, origin and implications. Economic Geology: 90: 1841-1856.
Onasch, C.M., Vennemann, T.W. (1995) Disequilibrium partitioning of oxygen isotopes associated with sector zoning in quartz. Geology: 23: 1103-1106.
Rykart, R. (1995) Quarz-Monographie - Die Eigenheiten von Bergkristall, Rauchquarz, Amethyst, Chalcedon, Achat, Opal und anderen Varietäten. Ott-Verlag, Thun.
Stevens Kalceff, M.A., Phillips, M.R. (1995) Cathodoluminescence microcharacterization of the defect structure of quartz. Physics Review: B: 52: 3122-3134.
Gratz, A.J., Fisler, D.K., Bohor, B.F. (1996) Distinguishing shocked from tectonically deformed quartz by the use of the SEM and chemical etching. Earth and Planetary Science Letters: 142: 513-521.
Plötze, M., Wolf, D. (1996) EPR- und TL-Spektren von Quartz: Bestrahlungsabhängigkeit der [TiO4 -/Li +] 0-Zentren. Bericht derJahrestagung der Deutschen Mineralogischen Gesellschaft: 8: 217 (abstr.).
Gaines, R.V., Skinner, C.H.W., Foord, E.E., Mason, B., Rosenzweig, A., King, V.T. (1997) Dana's New Mineralogy: The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, 8th. edition: 1573.
Niedermayr, G. (1997) Neue Beobachtungen über Hohlkanäle in alpinen Quarzen. Mineralien-Welt: 8(4): 40-44.
Carpenter, M.A., Salje, E.K.H., Gaeme-Barber, A., Wruck, B., Dove, M.T., Knight, K.S. (1998) Calibration of excess thermodynamic properties and elastic constant variations associated with the α ↔ β phase transition in quartz. American Mineralogist: 83: 2-22.
Gautier, J.-M., Schott, J., Oelkers, E.H. (1998) An experimental study of quartz precipitation and dissolution rates at 200°C. Mineralogical Magazine: 62: 509-510.
Hertweck, B., Beran, A., Niedermayr, G. (1998) IR-spektroskopische Untersuchungen des OH-Gehaltes alpiner Kluftquarze aus österreichischen Vorkommen. Mitteilungen der österreichischen Mineralogischen Gesellschaft: 143: 304-306.
Schäfer, K. (1999) Vogelschnäbel und Sterne - Quarz-Zwillinge: Kristallographische Schätze aus Idar-Oberstein. Lapis Mineralien Magazin: 24(10): 19-26.
Von Goerne, G., Franz, G., Robert, J.L. (1999) Upper thermal stability of tourmaline + quartz in the system MgO–Al2O3–SiO2–B2O3–H2O and Na2O–MgO–Al2O3–SiO2–B2O3–H2O–HCl in hydrothermal solutions and siliceous melts. The Canadian Mineralogist: 37: 1025-1039.
Bachheimer, J.-P. (2000) Comparative NIR and IR examination of natural, synthetic, and irradiated synthetic quartz. European Journal of Mineralogy: 12: 975-986.
Ghent, E.D., Stout, M.Z. (2000) Mineral equilibria in quartz leucoamphibolites (quartz—garnet—plagioclase—hornblende calc-silicates) from southeastern British Columbia, Canada. The Canadian Mineralogist: 38: 233-244.
Bons, P.D. (2001) The formation of large quartz veins by rapid ascent of fluids in mobile hydrofractures. Tectonophysics: 336: 1-17.
Götze, J., Plötze, M., Fuchs, H., Habermann, D. (2001) Origin, spectral characteristics and practical applications of the cathodoluminescence (CL) of quartz - a review. Mineralogy and Petrology: 71: 225-250.
Skála R., Hörz F. (2001) Unit-cell dimensions of experimentally shock-loaded quartz revisited. Meteoritics & Planetary Science: 36: 192-193.
Monger, H.C., Kelly, E.F. (2002) Silica minerals. in Soil Mineralogy with Environmental Applications, Soil Science Society of America (Madison Wisconsin, USA) 611-636.
Schlegel, M.L., Nagy, K.L., Fenter, P., Sturchio, N.C. (2002) Structures of quartz (1010)- and (1011)-water interfaces determined by X-ray reflectivity and atomic force microscopy of natural growth surfaces. Geochimica et Cosmochimica Acta: 66(17): 3037-3054.
Hyrsl, J., Niedermayr, G. (2003) Magic World: Inclusions in Quartz / Geheimnisvolle Welt: Einschlüsse in Quarz. Bode Verlag GmbH, Haltern. [in English and German]
Rodgers, K.A., Hampton, W.A. (2003) Laser Raman identification of silica phases comprising microtextural components of sinters. Mineralogical Magazine: 67: 1-13.
Rudnick, R.L., Gao, S. (2003) 3.01 Composition of the continental crust. Treatise On Geochemistry, Volume 3: The Crust. Elsevier Ltd. 1st Edition, 1-64.
Wangen, M., Munz, I.A. (2004) Formation of quartz veins by local dissolution and transport of silica. Chemical Geology: 209: 179-192.
Basile-Doelsch, I., Meunier, J.D., Parron, C. (2005) Another continental pool in the terrestrial silicon cycle. Nature: 433: 399-402.
Botis, S., Nokhrin, S.M., Pan, Y., Xu, Y., Bonli, T. (2005) Natural radiation-induced damage in quartz. I. Correlations between cathodoluminescence colors and paramagnetic defects. The Canadian Mineralogist: 43: 1565-1580.
de Hoog, J.C.M., van Bergen, M.J., Jacobs, M.H.G. (2005) Vapour-phase crystallisation of silica from SiF4-bearing volcanic gases. Annals of Geophysics: 48: 775-785.
Dove, P.M., Han, N., De Yoreo, J.J. (2005) Mechanisms of classical crystal growth theory explain quartz and silicate dissolution behavior. Proceedings of the National Academy of Science: 102: 15357-15362.
Götze, J., Plötze, M., Trautmann, T. (2005) Structure and luminescence characteristics of quartz from pegmatites. American Mineralogist: 90: 13-21.
Walter, F. (2005) Anhydrit als Einschluss in alpinen Quarzen der Ostalpen. Carinthia II: 195./115.: 85-96.
Walter, F., Ettinger, K. (2005) The origin of hollow tubes in Alpine quartz crystals. 3rd Symposion of the Hohe Tauern National Park for Research in Protected Areas, September 15th to 17th, 2005, Castle of Kaprun, Conference volume: 245-249.
Choudhury, N., Chaplot, S.L. (2006) Ab initio studies of phonon softening and high-pressure phase transitions of α-quartz SiO2. Physical Review B: 73: 094304-11.
Grimmer, H. (2006) Quartz aggregates revisited. Acta Crystallographica Section A: 62: 103-108.
Enami, M., Nishiyama, T., Mouri, T. (2007) Laser Raman microspectrometry of metamorphic quartz: a simple method for comparison of metamorphic pressures. American Mineralogist: 92: 1303-1315.
Pati, J.K., Patel, S.C., Pruseth, K.L., Malviya, V.P., Arima, M., Raju, S., Pati, P., Prakash, K. (2007) Geology and geochemistry of giant quartz veins from the Bundelkhand craton, central India and their implications. Journal of Earth Systems Science: 116: 497-510.
Hebert L.B., Rossman G.R. (2008) Greenish quartz found at the Thunder Bay Amethyst Mine Panorama, Thunder Bay, Ontario, Canada. The Canadian Mineralogist: 46: 111-124.
Ries, G., Menckhoff, K. (2008) Lösung und Neuwachstum auf Quarzkörnern eiszeitlicher Sande aus dem Hamburger Raum. Geschiebekunde aktuell: 24: 13-24.
Baur, W.H. (2009) In search of the crystal structure of low quartz. Zeitschrift für Kristallographie: 224: 580-592.
Botis, S.M., Pan, Y. (2009) Theoretical calculations of [AlO4/M+]0 defects in quartz and crystal-chemical controls on the uptake of Al. Mineralogical Magazine: 73: 537-550.
Korsakov, A.V., Perraki, M., Zhukov, V.P., De Gussem, K., Vandenabeele, P., Tomilenko, A.A. (2009) Is quartz a potential indicator of ultrahigh-pressure metamorphism? Laser Raman spectroscopy of quartz inclusions in ultrahigh-pressure garnets. European Journal of Mineralogy: 21: 1313-1323.
Lehmann, K., Berger, A., Götte, T., Ramseyer, K., Wiedebeck, M. (2009) Growth related zonations in authigenic and hydrothermal quartz characterized by SIMS, EPMA-, SEM-CL- and SEM-CC-imaging. Mineralogical Magazine: 73: 633-643.
Sunagawa, I., Iwasaki, H., Iwasaki, F. (2009) Growth and Morphology of Quartz Crystals: Natural and Synthetic. Terrapub, Tokyo, 201pp.
Thompson, R.M., Downs, R.T. (2010) Packing systematics of the silica polymorphs: The role played by O-O nonbonded interactions in the compression of quartz. American Mineralogist: 95: 104-111.
Wagner, T. Boyce, A.J., Erzinger, J. (2010) Fluid-rock interactions during formation of metamorphic quartz veins: a REE and stable isotope study from the Rhenish Massif, Germany. American Journal of Science: 310: 645-682.
Seifert, W., Rhede, D., Thomas, R., Forster, H.-J., Lucassen, F., Dulski, P., Wirth, R. (2011) Distinctive properties of rock-forming blue quartz: inferences from a multi-analytical study of submicron mineral inclusions. Mineralogical Magazine: 75: 2519-2534.
Götte, T., Ramseyer, K. (2012) Trace element characteristics, luminescence properties and real structure of quartz. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 265-285.
Götze, J. (2012) Classification, mineralogy and industrial potential of SiO2 minerals. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 1-27.
Götze, J. (2012) Mineralogy, geochemistry and cathodoluminescence of authigenic quartz from different sedimentary rocks. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 287-306.
Haus, R., Prinz, S., Priess, C. (2012) Assessment of high purity quartz resources. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 29-51.
Henn, U., Schultz-Guettler, R. (2012) Review of some current coloured quartz varieties. Journal of Gemmology: 33(1-4): 29-43.
Kempe, U., Götze, J., Dombon, E., Monecke, T., Poutivtsev, M. (2012) Quartz regeneration and its use as a repository of genetic information. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 331-355.
Li, Z., Pan, Y. (2012) First-principles calculations of the E'1 center in quartz: structural models, 29Si hyperfine parameters and association with Al impurity. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 161-175.
Müller, A., Wanvik, J.E., Ihlen, P.M. (2012) Petrological and chemical characterization of high-purity quartz deposits with examples from Norway. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 71-118.
Plötze, M., Wolf, D., Krbetschek, M.R. (2012) Gamma-irradiation dependency of EPR and TL-spectral of quartz. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 177-190.
Rusk, B. (2012) Cathodoluminescence textures and trace elements in hydrothermal quartz. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 307-329.
Scholz, R., Chaves, M.L.S.C., Krambrock, K., Pinheiro, M.V.B., Barreto, S.B., de Menezes, M.G. (2012) Brazilian quartz deposits with special emphasis on gemstone quartz and its color treatment. in: Götze, J., Möckel, R., editors. Quartz: Deposits, mineralogy and analytics. Springer Verlag, 139-159.
Deer, W.A., Howie, R.A., Zussman, J. (2013) An introduction to the rock-forming minerals. Mineral Society of Great Britain and Ireland. 510pp.
Pabst, W., Gregorová, E. (2013) Elastic properties of silica polymorphs - a review. Ceramics - Silikáty: 57: 167-184.
White, W.M., Klein, E.M. (2014) 4.13 Composition of the oceanic crust. Treatise On Geochemistry, Volume 4: The Crust. Elsevier Ltd. 2nd Edition, 1-64.
Zhang, S., Liu, Y. (2014) Molecular-level mechanisms of quartz dissolution under neutral and alkaline conditions in the presence of electrolytes. Geochemical Journal: 48(2): 189-205.
Eder, S.D., Fladischer, K., Yeandel, S.R., Lelarge, A., Parker, S.C., Søndergård, E., Holst, B. (2015) A giant reconstruction of α-quartz (0001) interpreted as three domains of nano Dauphine twins. Nature, Scientific Reports: 5: 14545. doi: 10.1038/srep14545
Frelinger, S.N., Ledvina, M.D., Kyle, J.R., Zhao, D. (2015) Scanning electron microscopy cathodoluminescence of quartz: Principles, techniques and applications in ore geology. Ore Geology Reviews: 65: 840-852.
Momma, K., Nagase, T., Kuribayashi, T., Kudoh, Y. (2015) Growth history and textures of quartz twinned in accordance with the Japan law. European Journal of Mineralogy: 27: 71-80.
Skalwold, E.A., Bassett, W.A. (2015) Quartz: a bull’s eye on optical activity. Mineralogical Society of America, Chantilly, VA, 16 pages. ISBN 978-0-939950-00-3 [booklet, abstract and free download on the MSA website: http://www.minsocam.org/msa/openaccess_publications/#Skalwold_02]
Skalwold, E.A., Bassett, W.A. (2015) Double trouble: navigating birefringence. Mineralogical Society of America, Chantilly, VA, 20 pages. ISBN 978-0-939950-02-7 [booklet, abstract and free download on the MSA website: http://www.minsocam.org/msa/openaccess_publications/#Skalwold_01]
Vinx, R. (2015) Gesteinsbestimmung im Gelände. Springer Verlag, Berlin, Heidelberg, 480pp.
Calvo, M. (2016) Minerales y Minas de España. Vol VIII. Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399pp. [in Spanish]
Lin, X., Heaney, P.J. (2017) Causes of iridescence in natural quartz. Gems & Gemology: 53: 68-81.
Glazer, A.M. (2018): Confusion over the description of the quartz structure yet again. Journal of Applied Crystallography 51, 915-918.
Shigeru Ohba (2019): More fun with quartz crystals! IUCr Newsletter 27 (1). [https://www.iucr.org/news/newsletter/etc/articles?issue=141171&result_138339_result_page=9]
Hertweck, B., Beran, A. & Niedermayr, G. (2019): Der OH-Gehalt von Kluftquarzen aus den österreichischen Alpen. Mitteilungen der Österreichischen Mineralogischen Gesellschaft 165, 99-117. [https://www.uibk.ac.at/mineralogie/oemg/bd_165/oemg_2019_hertweck.pdf]
Akhavan, A. (2020) Die Flächen der Quarzkristalle. Teil I: Die sieben Grundformen. Mineralien Welt: 31(2): 34-53.
Stalder, R. (2021): OH point defects in quartz – a review. Europen Journal of Mineralogy: 33: 145–163; https://forum.amiminerals.it/viewtopic.php?f=5&t=16974&sid=a600cc655cd57435ba9f078b3d461169
Farfan, G.A., Rakovan, J., Ackerson, M.R., Andrews, B.J., Post, J.E. (2021) The origin of trapiche-like inclusion patterns in quartz from Inner Mongolia, China. American Mineralogist: 106: 1797-1808.
Akhavan, A. (2021) Die Flächen der Quarzkristalle. Teil II: Rhomboeder, oberflächlich betrachtet. Mineralien Welt: 32(6): 42-62.
Murri, M., Prencipe, M. (2021): Anharmonic Effects on the Thermodynamic Properties of Quartz from First Principles Calculations. Entropy: 23: 1366.
Sun, Liang, Huan Zhang, Zanyang Guan, Weiming Yang, Youjun Zhang, Toshimori Sekine, Xiaoxi Duan, Zhebin Wang, and Jiamin Yang. (2021) "Sound Velocity Measurement of Shock-Compressed Quartz at Extreme Conditions" Minerals 11, no. 12: 1334. https://doi.org/10.3390/min11121334
Keyser, W. (2021): Quartz chemistry of granitic pegmatites: Implications for classification, genesis and exploration. QUARTZ 2021: International Symposium on Quartz, Tønsberg, Norway, NGF Abstracts and Proceedings, Volume 2, 11. [https://www.researchgate.net/publication/357630925_Quartz_chemistry_of_granitic_pegmatites_Implications_for_classification_genesis_and_exploration]
Shah, Sajjad Ahmad, Yongjun Shao, Yu Zhang, Hongtao Zhao, and Lianjie Zhao. (2022) "Texture and Trace Element Geochemistry of Quartz: A Review" Minerals 12, no. 8: 1042. https://doi.org/10.3390/min12081042
Bob Morgan (2022) Reichenstein-Grieserntal Quartz Twins: Two Angles Named in a single Twin Law. Mineralogical Record 53:739-754
Internet Links for Quartz
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Significant localities for Quartz
Showing 293 significant localities out of 91,220 recorded on mindat.org.
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ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Afghanistan | |
| Ikram Mineralogy |
Argentina | |
| [var: Citrine] Raúl Jorge Tauber Larry´s collection. |
Australia | |
| [var: Citrine] Patrick Gundersen |
| [var: Amethyst] McColl, D. (2002) Quartz Scepter Crystals from the Entia Valley, Harts Range, Central Australia. Mineralogical Record, 33(6), 515. |
| Bottrill (unpub) |
| M Latham collection |
| [var: Smoky Quartz] Bottrill, R.S. & Baker, W.E. (2008) A Catalogue of the Minerals of Tasmania. Bull. 73. Tasmanian Geological Survey |
R Bottrill, unpub data; Bottrill, R.S. & Baker, W.E. (2008) A Catalogue of the Minerals of Tasmania. Bull. 73. Tasmanian Geological Survey | |
| [Jasper var: Darlingite] Trans. R. Soc. Victoria, 1866, VII, 80; Proc. R. Soc. Victoria, 1897, N.S. IX, 86 |
Austria | |
| [var: Amethyst] Kandutsch, Wachtler (2000), Die Kristallsucher, Band 2, Athesiadruck Bozen |
| [var: Smoky Quartz] Wachtler, Kandutsch, Die Kristallsucher, Christian Weise Verlag, Bozen 2000 |
[var: Smoky Quartz] G. Niedermayr, I. Praetzel: Mineralien Kärntens, 1995 | |
[var: Rutilated Quartz] Rudolf Hasler Collection | |
| [var: Amethyst] Dr. H. Weninger (1976) Mineral-Fundstellen Steiermark und Kärnten |
| G. Niedermayr, I. Praetzel: Mineralien Kärntens, 1995 |
[var: Rock Crystal] G. Niedermayr: Carinthia II 184./104.:254-255 (1994) | |
| Gerd Stefanik |
| Rudolf Hasler Collection |
| [var: Rock Crystal] Niedermayr, G., Praetzel, I. (1995) Mineralien Kärntens. Verlag des Naturwissenschaftlichen Vereins für Kärnten, Klagenfurt, 232 pages, [in German]. |
Rudolf Hasler; Rudolf Hasler Collection | |
| G. Niedermayr, I. Praetzel: Mineralien Kärntens, 1995; Alker, A. (1975): Über die Mineralkluft im Amphibolit von Burgegg, Steiermark. Mitteilungen des naturwissenschaftlichen Vereins für Steiermark 105, 21-24. |
| [var: Amethyst] Christian Bracke Collection / Mineralien Welt 15 (6), 35-37 Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie |
| [var: Amethyst] Lapis 29(9):32 (2004) |
Belgium | |
| [var: Rock Crystal] Harjo Neutkens collection |
| [var: Rock Crystal] Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French). |
| Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002) Les minéraux de Belgique. 2ème édition, Muséum des Sciences Naturelles, Bruxelles, Belgium, 304 pages (in French). |
Bolivia | |
| Collections of Alfredo Petrov and Dr. Jaroslav Hyrsl. |
| [var: Amethyst] Alfredo Petrov, field trip observations, 2005. |
| [var: Amethyst] John Betts website |
[var: Amethyst] Josep Sanchez-Lafuente collection. | |
Bosnia and Herzegovina | |
| G. Sijarić (1985) Optical features of Albites in triassic and jurassic magmatic rocks in Bosnia. Faris Musija |
Brazil | |
| [var: Rose Quartz] Natural History Museum Vienna collection |
RSA MINERAIS | |
| [var: Amethyst] Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (pp. 82, 122).; Gilg, H.A., Morteani, G., Kostitsyn, Y., Preinfalk, C., Gatter, I., and Strieder, A.J. (2003) Genesis of amethyst geodes in basaltic rocks of the Serra Geral Formation (Ametista do Sul, Rio Grande do Sul, Brazil): a fluid inclusion, REE, oxygen, carbon, and Sr isotope study on basalt, quartz, and calcite. Mineralium Deposita, 38(8), 1009-1025.; Mossmann, D.J., Ehrman, J.M., Brüning, R., Semple, L., and Groat, L.A. (2009) "Skunk calcite". Mineral Paragenesis in an amethyst geode from Ametista, Rio Grande do Sul, Brazil. Mineralogical Record, 40, 121-125. |
[var: Amethyst] [www.johnbetts-fineminerals.com]; Sauer, J.R. (1982) Brazil, Paradise of Gemstones. Gemological Institute of America, 135 pp. (pp. 80-81). | |
Bulgaria | |
| [var: Amethyst] Ivan Pojarevski (bulgarianminerals.com) specimens. |
Canada | |
| Ann P. Sabina Rocks and Minerals for the collector 1991 |
| Robinson, G.W., et al. (1992) What's New in Minerals. The Mineralogical Record: 23(5): 428. |
| [MinRec 21:533]; Dennis C. Arne, L. W. Curtis, S. A. Kissin (1991) Internal zonation in a carbonate-hosted Zn-Pb-Ag deposit, Nanisivik, Baffin Island, Canada. Economic Geology ; 86 (4): 699–717. |
| [var: Amethyst] Matthew Neuzil Collection |
[var: Amethyst] Mason, A. (1976) The world of Rocks and Minerals. New York, N.Y., Larousse & Co., 108 pages.; Satterly, J. (1977) A Catalogue of the Ontario Localities Represented by the Mineral Collection of the Royal Ontario Museum; Ontario Geological Survey Miscellaneous Paper MP70, 464 pages.; Elliott, D.G. (1982) Amethyst from the Thunder Bay Region, Ontario. Mineralogical Record, 13, 67-70.; Grice, Joel D. (1989) Amethyst from Thunder Bay, Ontario: An Ancient Amulet. In: Famous mineral localities of Canada. Published by Fitzhenry & Whiteside Limited & the National Museum of Natural Sciences, 190 pages: 68-72; 156. | |
| [var: Amethyst] Rocks & Minerals (xxxx) 59, 262-266.; Grice, Joel D. (1989) Amethyst from Thunder Bay, Ontario: An Ancient Amulet. In: Famous mineral localities of Canada. Published by Fitzhenry & Whiteside Limited & the National Museum of Natural Sciences, 190 pages: 68-72. |
Ontario Gem Company | |
China | |
| [var: Amethyst] Moore, T.P. (2006): Mineralogical Record 37(5), 477-485. |
| [Chalcedony var: Agate] Rob Woodside collection |
Colombia | |
| Saenz, L. D. (2005): PETROGRAFÍA Y GEOTERMOMETRÍA DE LOS YACIMIENTOS DE ESMERALDA DE PEÑA BLANCA (SAN PABLO DE BORBUR, BOYACÁ, COLOMBIA) |
Ecuador | |
| [var: Prase] Alejandro Félix Gutiérrez |
France | |
| G. Signorelli |
| Weiss, C.S. (1829) Über die herzförmig genannten Zwillingskrystalle von Kalkspath, und gewisse analoge von Quarz. Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin: 77-87.; Des Cloizeaux, A. (1855) Mémoire sur la cristallisation et la structure intérieure du quartz. Annales de Chimie et de Physique, 3ème série, 45, 129-316; Mallet-Bachellier, Paris, 188 pp. + 4 tables; Weil, R. (1930) Nouvelles observations sur le quartz. Type L. Comptes rendus hebdomadaires des séances de l'Académie des sciences, 191, 380-382.; Weil, R. (1931) Quelques observations concernant la structure du quartz. Compte Rendu 1er Réunion de l'Institut d'Optique: 2-11.; Poty, B. (1967) La croissance des cristaux de quartz dans le filons sur l'exemple du filon de La Gardette (Bourg d'Oisans) et des filons du massif du Mont-Blanc. Thesis. Minéralogie. Université de Nancy.; Bariand, P., Cesbron, F., Geffroy, J. (1977) Les minéraux, leurs gisements, leurs associations. Editions Minéraux et Fossiles, BRGM.; Belot, Victor R. (1978) Guide des minéraux, coquillages et fossiles: où les trouver en France, comment les reconnaître et les collectionner (Guides Horay). Pierre Horay (Ed.), 224 pp. |
| [var: Smoky Quartz] F. Gonnard (1906) - Minéralogie des départements du Rhône et de la Loire, pp: 6 & 36 |
[var: Smoky Quartz] F. GONNARD (1906) - Minéralogie des départements du Rhône et de la Loire | |
| [var: Amethyst] 207433; Jonathan Plasse collection S. Berger Collection |
| Favreau G., Legris J-R., Dardillac M. (1996), La Verrière (Rhône): Histoire et Minéralogie, Le Cahier des Micromonteurs, n°3, pp:3-28 |
| Harjo |
| Alain Steinmetz and Thierry Brunsperger Collection |
| Aufschluss 1/85 |
| Rostan P. (2002), Cristaux de quartz d'habitus fenestré dans les Alpes du Sud, Le Règne Minéral, n°45, pp: 5-17 |
| Thierry JEAN |
Hungary | |
| Szakáll & Jánosi: Minerals of Hungary, 1995 |
India | |
| [var: Amethyst] Thomas P. Moore The Mineralogical Record - Archived What's New Articles: posted on 3/3/2006 |
Ireland | |
| O’Reilly, C., Feely, M., McArdle, P., Mc Dermot, C. Geoghegan, M. & Keary, R. (1997). Mineral localities in the Galway Bay Area. Geol. Surv. Ireland. Special Report Series. RS/97/1(Mineral Resources) ISSN0790-0279, 70p. & 1:150,000 Geological and Mineral Localities Map of the Galway Bay Area. |
| [var: Amethyst] Nicholson, A. (1847). Ireland's welcome to the stranger: or An excursion through Ireland, in 1844 & 1845, for the purpose of personally investigating the condition of the poor. By A. Nicholson. Baker and Scribner. |
| Barry Flannery collection |
| Stephen Moreton |
| Barry Flannery (Personal Communication) |
| Moreton, S. (1999) Mineralogical Record, 30, 99-106. Barry Flannery (Personal Observation) |
| [var: Smoky Quartz] R Lawson & S Moreton Communication |
Italy | |
| Piccoli, G.C., Maletto, G., Bosio, P., and Lombardo, B. (2007) Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" di Alba, L'Artigiana Srl - Azienda Grafica, Alba (Cuneo), 607 pages. Barelli, V. (1835) Cenni di statistica mineralogica degli Stati di S.M. il Re di Sardegna, ovvero Catalogo ragionato della raccolta formatasi presso l'Azienda Generale dell'Interno. Tipografia Giuseppe Fodratti, Torino, 686 pages; Jervis, G. (1873) I tesori sotterranei dell'Italia. Vol. 1: Regioni delle Alpi. Ermanno Loescher, Torino, XV+410 pages. |
| Natural History Museum Vienna Collection |
| Gambari, L. (1868) Descrizione dei quarzi di Porretta. Atti della Società dei naturalisti e matematici di Modena, 3, 1-19; Bombicci, L. (1869) La collezione dei cristalli di quarzo aeroidro di Porretta. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 2, 9, 56-60; Bombicci, L. (1874) Descrizione della mineralogia generale della provincia di Bologna. Seconda parte. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 3, 5, 105-222; Jervis, G. (1874) I tesori sotterranei dell'Italia. Vol. 2: Regione dell’Appennino e vulcani attivi e spenti dipendentivi. Ermanno Loescher, Torino, XVIII+624 pp.; Chamberlin, R. T. (1908) The gases in rocks. Carnegie Institute of Washington, Publication 106, page 41; De Michele, V. (1974) Guida mineralogica d'Italia. Istituto Geografico De Agostini, Novara, 2 vol., 408 pp.; Mullis, J. (1988) Rapid subsidence and upthrusting in the Northern Apennines, deduced by fluid inclusion studies in quartz crystals from Poretta Terme. Schweizerische Mineralogische und Petrographische Mitteilung, 68, 157-170; Bargossi, G.M., Gamberini, F., Gasparotto, G., Grillini, G.C., Marocchi, G. (2004) Dimension and ornamental stones from the Tosco-Romagnolo and Bolognese Apennine. Periodico di Mineralogia, 73, Special Issue 3, 171-195; Castagliola, P., Cipriani, V., Pratesi, G., Niedermayr, G. (2006) Die 'Quarz-Diamanten' aus dem Apennin in Italien (Toskana und Emilia Romagna). Mineralien-Welt, 17, 2, 58-66.; Olivieri, O. S. and Miglioli, A. (2021): Hopper quartz crystals from Porretta Terme and Val Nervia, northern Italy. Australian Journal of Mineralogy 22 (2), 13-29. |
Bombicci, L. (1874) Descrizione della mineralogia generale della provincia di Bologna. Seconda parte. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 3, 5, 105-222; De Michele, V. (1974) Guida mineralogica d'Italia. Istituto Geografico De Agostini, Novara, 2 vol., 408 pp. | |
Bombicci, L. (1869) La collezione dei cristalli di quarzo aeroidro di Porretta. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 2, 9, 56-60. Bombicci, L. (1874) Descrizione della mineralogia generale della provincia di Bologna. Seconda parte. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 3, 5, 105-222. | |
| Bombicci, L. (1874) Descrizione della mineralogia generale della provincia di Bologna. Seconda parte. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 3, 5, 105-222; De Michele, V. (1974) Guida mineralogica d'Italia. Istituto Geografico De Agostini, Novara, 2 vol., 408 pp.; Bargossi, G.M., Gamberini, F., Gasparotto, G., Grillini, G.C., Marocchi, G. (2004) Dimension and ornamental stones from the Tosco-Romagnolo and Bolognese Apennine. Periodico di Mineralogia, 73, Special Issue 3, 171-195. |
| De Michele, V. (1974). Guida mineralogica d'Italia. Istituto Geografico De Agostini, Novara, 2 vol. |
| [var: Amethyst] Olimpo, Guido (1981) Ritrovamenti mineralogici nelle Valli del Gesso (Cuneo). Rivista Mineralogica Italiana, 5, 1 (1-1981), 13-18; Mari, Danielle, and Mari, Gilbert (1982) Mines et minéraux des Alpes-Maritimes. Editions Serre, Nice, 282 pp.; Piccoli, Gian Carlo (2002) Minerali delle Alpi Marittime e Cozie Provincia di Cuneo. Associazione Amici del Museo "F. Eusebio" di Alba, L'Artistica Savigliano, Savigliano (Cuneo), 362 pp.; Piccoli, Gian Carlo, Maletto, Gaspare, Bosio, Paolo, Lombardo, Bruno (2007) Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" di Alba, L'Artigiana Srl - Azienda Grafica, Alba (Cuneo), 607 pp. |
| [var: Amethyst] Torti, R. (1973) La miniera di Traversella e i suoi minerali. Gruppo Mineralogico Lombardo, Ed., Milano, 54 pp.; De Michele, V. (1974) Guida mineralogica d'Italia. Ed. De Agostini, Novara, 2 vol., 408 pp.; Gramaccioli, C.M. (1975) Minerali alpini e prealpini. Istituto Italiano Edizioni Atlas, Bergamo, 2 vol., 472 pp.; GMV Gruppo Mineralogico Valchiusella, Pagano, R., and Barresi, A. (2005) La miniera di Traversella: passato, presente e futuro. Rivista Mineralogica Italiana, 29, 1 (1/2005), 8-26; Piccoli, G.C., Maletto, G., Bosio, P., and Lombardo, B. (2007) Minerali del Piemonte e della Valle d'Aosta. Associazione Amici del Museo "F. Eusebio" di Alba, Ed., Alba, 607 pp. Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie |
| [var: Smoky Quartz] |
| [var: Amethyst] No reference listed |
| Alessandro Genazzani collection |
Barsotti, G., & Nannoni, R. (2006). Rocce, minerali e miniere delle isole dell'Arcipelago Toscano. Pacini editore, 152 pp.; F. Millosevich (1914) - I 5000 Elbani del Museo di Firenze - R. Ist. Studi Sup. Prat. Perf. Firenze; Giuliano bettini collection | |
| |
| Orlandi P., Dini A., Gemignani E., Pierotti L., Quilici U., Romani U., 2002. Paragenesi alpine nelle Alpi Apuane: I minerali delle vene di quarzo della Valle dell'Acqua Bianca, Gorfigliano (LU) Riv. Mineral. It., 26, 4: 216-223 |
| [var: Smoky Quartz] Baldi M., 1982. La miniera del Pollone a Valdicastello. Riv. Miner. Ital., 6: 46-58. |
| Del Riccio, A. (1597) Istoria delle pietre. Barocchi, P., ed., 1979, anastatic reprint of the original manuscript preserved in the Biblioteca Riccardiana (Riccardian Library) in Florence, Studio per Edizioni Scelte, Firenze, 280 pp.; Gnoli, R., and Sironi, A., eds., 1996, anastatic reprint, Umberto Allemandi & C., Torino, 253 pp.; Aldrovandi, U. (1648) Musaeum metallicum. Liber V. Typis Io. Baptistae Ferronii, Bononia, page 943; Targioni Tazzetti, G. (1779) Relazioni d'alcuni viaggi fatti in diverse parti della Toscana per osservare le produzioni naturali, e gli antichi monumenti di essa. Tomo 12. Gartano Cambiaghi Stamp. Granducale, Firenze, VII+446 pp.; Spallanzani, L. (1784) Lettera seconda relativa a diversi oggetti fossili e montani al Sig. Carlo Bonnet scritta il giorno 12 Febbraio 1784. Memorie di Matematica e Fisica della Società Italiana, tomo 2, parte 2, 861-899; Rose, G. (1844) Über das Krystallisationssystem des Quarzes. Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin, Aus dem Jahre 1844, 217-274; Des Cloizeaux, A. (1855) Mémoire sur la cristallisation et la structure intérieure du quartz. Annales de Chimie et de Physique, 3ème série, 45, 129-316; Mallet-Bachellier, Paris, 188 pp. + 4 tables; D'Achiardi, A. (1872-73) Mineralogia della Toscana. Tipografia Nistri, Pisa, 2 vol., 678 pp.; Bombicci, L. (1892 a) Sulla coesistenza delle due inverse plagiedrie sopra una faccia di un cristallo di quarzo e sulle spirali di Airy presentate da una sezione ottica dello stesso cristallo e di altri. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 5, 2, 722-729; Bombicci, L. (1892 b) Sulle modificazioni degli spigoli verticali nei cristalli di quarzo di Carrara e su quelle che strutturalmente vi corrispondono nei cristalli di altre specie minerali. Memorie della R. Accademia delle Scienze dell'Istituto di Bologna, serie 5, 2, 747-761; Aloisi, P. (1909) Il quarzo dei marmi di Carrara. Atti della Società Toscana di Scienze Naturali, Memorie, 25, 87-125; Tonani, F. (1955) Morfologia fine di cristalli di quarzo delle Alpi Apuane. Rendiconti della Società Mineralogica Italiana, 11, 288-315; Orlandi, P., Bracci, G., Dalena, D., Duchi, G., and Vezzalini, G. (1980) I minerali delle geodi della formazione marmifera di Carrara. Atti della Società Toscana di Scienze Naturali, Memorie, serie A, 87, 93-124; Orlandi, P., and Franzini, M. (1994) I minerali del marmo di Carrara. Cassa di Risparmio di Carrara - Amilcare Pizzi Editore S.p.A., Milano, 109 pp.; Orlandi, P., and Criscuolo, A. (2009) Minerali del marmo delle Alpi Apuane. Parco delle Alpi Apuane - Pacini Editore, Ospedaletto-Pisa, 180 pp.; Morino, A. and Passarino, G. (2014) Il quarzo dei marmi di Carrara. Rivista Mineralogica Italiana, 38, 1 (1-2014), 36-41; Biagioni, C., Orlandi, P., Camarda, S., Chinellato, M., Appiani, R., Del Chiaro, L., and Sanguineti, G. (2019) Minerals from marbles of Carrara and the Apuan Alps. LoGisma editore, Vicchio (Firenze) - Musumeci S.p.A., Quart (Aosta), 144 pp. |
Kazakhstan | |
| [var: Amethyst] M. Chinellato, pers. comm., 2007; Evseev, A. A. [Евсеев, А.А.] (2004) Atlas of the World for mineralogist [Атлас мира для минералога]. Ecost Association [Ассоциация Экост], Moscow, page 146 (in Russian). Lieber, W. (1994) Amethyst - Geschichte, Eigenschaften, Fundorte. Christian Weise Verlag, München. |
| [Chalcedony var: Agate] Bespaev, Kh.A., Uzhkenov, B.S., Aliaksarov, S.A., and Egembaev, K.M. [Беспаев, Х.А., Ужкенов, Б.С., Алиаскаров, С.А., и Егембаев, К.М.] (2001) Gemstones of Kazakhstan. Reference book. Volume II. Semi-precious and ornamental stones [Самоцветы Казахстана. Справочник. Том II. Ювелирно-поделочные и поделочные самоцветы]. Information-Analytical Center for Geology and Mineral Resources of the Republic of Kazakhstan [Информационно-аналитический центр геологии и минеральных ресурсов Республики Казахстан], Almaty, pages 106-107 (in Russian). |
Kenya | |
| [var: Amethyst] Moore, T. P. (2010): Denver Show 2009. Mineralogical Record, 41: 88-97 |
Madagascar | |
| [var: Amethyst] Moore, T.(2001): What is new in Minerals. Tuscon Show 2001. Mineralogical Record 32(3), p 252 Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie |
| [var: Amethyst] http://www.madaquartz.com/pages/amethyste.html |
Mexico | |
| [var: Amethyst] [www.johnbetts-fineminerals.com] Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie |
[var: Amethyst] Kipfer, A. (1974) Ein neues Hobby: Kleinmineralien sammeln und präparieren. Franckh'sche Verlagshandlung, W. Keller & Co., Stuttgart, 64 pp.; Mineralogical Record (2000) 31(4) and opening spread. | |
| [var: Amethyst] Min Rec 35:6 pp29-37 |
| [var: Amethyst] [www.johnbetts-fineminerals.com] |
Morocco | |
| [var: Amethyst] Jordi Fabre [Pers. Com. 2009]; Jordi Fabre Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie |
Namibia | |
| [var: Amethyst] [www.thamesvalleyminerals.com] Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie |
| [var: Amethyst] Peter Seroka collection |
Nepal | |
| Calonge, Y.(2011): Un extraordinaire groupe de quartz au Népal. Le Règne Minéral. 97: 25 |
Niger | |
| [var: Amethyst] Sylvain Leroux information |
Norway | |
| Revheim, O. (2006) Landsverk 1, Jokeli-bruddet i Evje. Norsk Bergverksmuseum Skrift. 33: 41-50 Werner, R. (2017) Evje Mineralsti - Landsverk Quarries. Setesdalsmuseet/Aust-Agder museum and archive. 36 pp. |
| [var: Amethyst] Moløkken, A. (1997): Ametysten fra Stange og Løten kommuner i Hedmark. STEIN 24 (2), 50-52; Mineralien-Welt 20 (6), 72-73 (2009) Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie |
| Álvaro Chicote Collection |
| [var: Amethyst] Moløkken, Arne (1990):Ametyst i Stange,Hedemark.STEIN 17 (3),14 (in norwegian) |
| [var: Amethyst] Nordrum, F.S., Larsen, A.O., Bergstrøm, T. & Larsen, S. (1997): Die Zeptheramethyste von Holmestrand. Mineralien Welt. 8 (4): 45-50 |
Peru | |
| Hyrsl & Rosales (2003) Mineralogical Record, 34, 241-254.; Econ Geol (1985) 80:416-478 |
| Mineralogical Record 28, No. 4 (1997); collections of Rock Currier, Jack Crowley, Jaroslav Hyrsl and Alfredo Petrov.; Hyrsl & Rosales (2003) Mineralogical Record, 34, 241-254.; Hyrsl & Rosales (2003) Mineralogical Record, 34, 241-254. |
| Mi.Rec. 28, no.4 (1997) |
Poland | |
| Schumacher K. (1878) Die Gebirgsgruppe des Rummelberges bei Strehlen. Zeitschrift Deutsche Geologische Gesellschaft. Bd. 30. Berlin (In German) |
Portugal | |
| Leal Gomes, C., Azevedo, A., Lopes Nunes, J., & Dias, P. A. (2009). Phosphate fractionation in pegmatites of Pedra da Moura II claim–Ponte da Barca–Portugal. Estudos Geológicos, 19(2), 172. |
Romania | |
| [var: Amethyst] W. Stöhr (2001): Porkura - ein klassischer Amethystfundort in Rumänien Lapis 26 (9), 13-xx; Rob Lavinsky |
| [var: Amethyst] Clain, E. & Haake, R. (2006): Die Blei-Zink-Lagerstätte von Turt, Oasgebirge, Rumänien. Mineralien-Welt 17 (5), 52-64. (in German) Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie |
Russia | |
| [var: Amethyst] Oleg Lopatkin Bukanov, V.V., Burlakov, E.V., Kozlov, A.V., Pozhidaev, N.A. (2012) Subpolar Urals: Minerals of the Rock Crystal Veins. Mineralogical Almanac:17(2), Moscow. |
| [var: Amethyst] [www.johnbetts-fineminerals.com] Lieber, W. (1994) Amethyst - Geschichte, Eigenschaften, Fundorte. Christian Weise Verlag, München. |
| [Chalcedony var: Agate] http://www.pegmatite.ru/My_Collection/mn/agate_lg.jpg; Godovikov, A.A., Ripinen, O.I., and Motorin, S.G. [Годовиков, А.А., Рипинен, О.И., и Моторин, С.Г.] (1987) Agates [Агаты]. Nedra [Недра], Moscow, 368 pp. (in Russian); Volarovich, G.P. [Воларович, Г.П.] (1991) Colored stones of Podmoskovye [Цветные камни Подмосковья]. Nedra [Недра], Moscow, 208 pp. (in Russian); Feklichev, V.G. [Фкеличев, В.Г.] (1998) Mineral diversity of the Moscow region [Минералогическое разнообразие Подмосковья]. Sredi Mineralov (Almanac) [Среди минералов (альманах)], 103-112 (in Russian); Evseev, A. A. [Евсеев, А.А.] (2004) Atlas of the World for mineralogist [Атлас мира для минералога]. Ecost Association [Ассоциация Экост], Moscow, page 23 (in Russian). |
| [var: Ferruginous Quartz] Amir Akhavan |
| [World of Stones 2:93]; Pavel M. Kartashov data |
| [var: Rock Crystal] [World of Stones 2/93 p.35] |
Slovakia | |
| [var: Amethyst] Ozdín, Daniel, Krejsek, Štepán (2016) Famous mineral localities: Banská Štiavnica (Schemnitz, Selmecbánya), Slovak Republic. The Mineralogical Record, 47 (3) 254-318 https://www.mindat.org/reference.php?id=12910402 |
| [Chalcedony var: Agate] Ozdín D. & Števko M., 2010: Unikátny výskyt achátov v serpentinizovaných peridotitoch v Dobšinej. Minerál, 18, 4, 331-335. |
| Slavomír ŠIMKO |
Slovenia | |
| Matija Vukovski Collection |
South Africa | |
| [var: Milky Quartz] Paul Meulenbeld collection Photo ID: 881739 |
| [var: Amethyst] www.mindat.org/mesg-55-48596.html Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie |
South Korea | |
| [var: Amethyst] Yang, K. H., Yun, S. H., & Lee, J. D. (2001). A fluid inclusion study of an amethyst deposit in the Cretaceous Kyongsang Basin, South Korea. Mineralogical Magazine, 65(4), 477-487. Lieber, W. (1994) Amethyst - Geschichte, Eigenschaften, Fundorte. Christian Weise Verlag, München. |
Spain | |
| Calvo, Miguel. (2016). Minerales y Minas de España. Vol. VIII. Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399 págs.; Calvo, M. (2016). Minerales y Minas de España. Vol. VIII. Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399 págs. |
| [var: Citrine] Arroyo, A. and Calvo, M. (1995). El cuarzo citrino de Villasbuenas (Salamanca). Revista de minerales. 1: 86-89. |
| [var: Amethyst] Curtó, C.; Mérida, J.C.; Evangelio, S.: Las amatistas de la cantera Massabé, Sils, Girona. Revista de Minerales, vol.III, nº 3 Marzo 2007. Calvo, Miguel. (2016). Minerales y Minas de España. Vol. VIII. Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399 págs. |
| Calvo, M. (2016). Minerales y Minas de España. Vol. VIII. Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399 págs. |
| [var: Smoky Quartz] Calvo, M., Viñals, J. and Vila, F. (2009) Mineralogy of the pegmatites and miarolitic cavities in the granitic batholit of Porriño, Pontevedra, galicia, Spain. Mineral Up, (2009-1), 6-23 |
| [var: Amethyst] Calvo, M. (1996). Mineralogía. La Unión. Bocamina, 2, 14-35 Calvo Rebollar, Miguel. (2016). Minerales y Minas de España. Vol. VIII. Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399 págs. |
| Calvo, M. (2016). Minerales y Minas de España. Vol VIII.Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399 págs. |
| Casanova Honrubia, Juan Miguel & Canseco Caballé, Manuel, 2002, Minerales de la Comunidad Valenciana : 237 p. Ed. Caja de Ahorros del Mediterráneo. Alicante Calvo, Miguel. (2016). Minerales y Minas de España. Vol. VIII. Cuarzo y otros minerales de la sílice. Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. 399 págs. |
Switzerland | |
| [var: Smoky Quartz] Stalder, H.A. (1964) Petrographische und mineralogische Untersuchungen im Grimselgebiet (mittleres Aarmassiv). Schweizerische Mineralogische und Petrographische Mitteilungen, 44, 187–398. |
| [var: Rock Crystal] Altmann, J.G. (1751) Versuch einer historischen und physischen Beschreibung der helvetischen Eisbergen. Heidegger und Compagnie, Zürich, 12 + 271 pp.; Waeber, A. (1889) Der Krystallfund am Zinkenstock 1719 nach David Märki’s Bericht von 1721. Jahrbuch des S.A.C. [Jahrbuch des Schweizer Alpen-Clubs], 25, 380-411; Hartmann, H. (1909) Hasli im Weissland vor 200 Jahren: unter Berücksichtigung seine Kristallindustrie. Blätter für bernische Geschichte, Kunst und Altertumskunde, 5, 43-64; Stalder, H.A. (1964) Petrographische und mineralogische Untersuchungen im Grimselgebiet (mittleres Aarmassiv). Schweizerische Mineralogische und Petrographische Mitteilungen, 44, 187–398; Stalder, H.A., Wagner, A., Graeser, S., and Stuker, P. (1998) Mineralienlexikon der Schweiz. Verlag Wepf & Co., Basel, pages 334 and 336; Artl, T. (2020) Nach 300 Jahren wiederentdeckt: Die Kristallkluft von 1719 am Zinggenstock, Schweiz. Lapis, 45, 6 (June 2020), 32–43; Artl, T., and Bolliger, (2020) Die Kristallhöhle von 1719 am Zinggenstock. Mitteilungen der Naturforschenden Gesellschaft in Bern, 77, 70-89. |
[var: Smoky Quartz] Stalder, H.A., Wagner, A., Graeser, S., and Stuker, P. (1998) Mineralienlexikon der Schweiz. Verlag Wepf & Co., Basel, pages 301 and 336. | |
| Jahn, S. (2004) Klassische Weltfundstelle: Val Giuv. Mineralien Welt, 15 (1): 34-61 |
| Taddei, C. (1937) Dalle Lepontine al Ceneri. Note di geo-mineralogia. Istituto Editoriale Ticinese, Bellinzona, 182 pp.; Weiß, S. (1982) Das Cavagnoli-Gebiet. Lapis, 7, 7, 17-25; Stalder, H. A., Wagner, A., Graeser, S., and Stuker, P. (1998) Mineralienlexikon der Schweiz. Verlag Wepf & Co. AG, Basel, page 209; Weiß, S., and Brack, P. (2018) Tessin. ExtraLapis, 55, 122 pp. |
Turkey | |
| [Chalcedony] Agricola (1546) De Natura Fossilium, p. 466 |
Uruguay | |
| [var: Amethyst] [www.johnbetts-fineminerals.com]; Giulio Morteani, Y. Kostitsyn, C. Preinfalk, H. A. Gilg (2010) The genesis of the amethyst geodes at Artigas (Uruguay) and the paleohydrology of the Guaraní aquifer: structural, geochemical, oxygen, carbon, strontium isotope and fluid inclusion study. International Journal of Earth Sciences 99:927-947 |
USA | |
| Min Rec 35:5 pp383-404, 419-420 |
| Smith, Arthur E. Jr. (1996) Collecting Arkansas Minerals. L. Ream Publishing, Idaho 149p |
| Jake Harper: Field work, 1990 - 2110. |
| [var: Amethyst] Calzia, J. P. et al. 1987. Mineral Resources of the Kingston Range Wilderness Study Area, San Bernardino County, California. U.S. Geological Survey Bulletin 1709-D, 34 p., maps. Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie |
| Ron Layton collection |
| [var: Amethyst] Rocks & Min.: 59:11. |
[Chalcedony] Personally collected by Donald Gilbert Garcia in 2016 | |
| [var: Milky Quartz] Eckel, E.B. (1997), Minerals of Colorado. |
| Rowan M. Lytle; Harold Moritz collection |
| [var: Amethyst] Kenneth Holt specimen (locality info corrected courtesy of John Betts); Mineralogical Record (1990) 21:203-213; Rocks & Minerals (1995) 70:396-409 |
| Wolfe, C. W. and Vilks, I. (1960): Pseudomorphs after Datolite, Prehnite and Apophyllite from East Granby, Connecticut. Am. Mineral. 45, 443-447. |
| Harold Moritz collection |
Januzzi, Ronald E. (1976), Mineral Localities of Connecticut and Southeastern New York State. The Mineralogical Press, Danbury, Connecticut. | |
| Harold Moritz collection |
| Januzzi, Ronald E. and David Seaman. (1976), Mineral Localities Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut. |
| Bill Barrett Coll.; Garabedian, James A. (1998), Secondary Mineralization of Half-Moon Vesicles in the Mesozoic Basalt of the O&G#2 Quarry, Woodbury, Connecticut. University of Connecticut Master of Science Thesis. |
| Rowan M. Lytle Collection |
| [var: Smoky Quartz] Davis, James W. (1901): The Minerals of Haddam, Conn. Mineral Collector, v. 8, no. 4, pp. 50-54, and no. 5, pp. 65-70.; Scovil, Jeffrey A. (1992): Famous Mineral Localities: the Gillette Quarry, Haddam Neck, Connecticut. (Mineralogical Record, 23(1):19-28.); Schooner, Richard. (1958) THE MINERALOGY OF THE PORTLAND-EAST HAMPTON-MIDDLETOWN-HADDAM AREA IN CONNECTICUT (With a few notes on Glastonbury and Marlborough). |
Seaman, David (1976): "Pegmatite Minerals of the World" in: Januzzi, Ronald E. and David Seaman.(1976): Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. (The Mineralogical Press: Danbury, Connecticut).; Harold Moritz field observations. | |
Williams (circa 1945 and 1899); Harold Moritz collection | |
| Schooner, Richard. (1955): 90 Minerals from 1 Connecticut Hill. Rocks & Minerals: 30(7-8): 351-8.; Cameron, Eugene N., Larrabee, David M., McNair, Andrew H., Page, James T., Stewart, Glenn W., and Shainin, Vincent E. (1954): Pegmatite Investigations 1942-45 New England; USGS Professional Paper 255: 333-338.; Schooner, Richard. (1958): The Mineralogy of the Portland-East Hampton-Middletown-Haddam Area in Connecticut (With a few notes on Glastonbury and Marlborough). Published by Richard Schooner; Ralph Lieser of Pappy’s Beryl Shop, East Hampton; and Howard Pate of Fluorescent House, Branford, Connecticut. |
| Specimens collected by Jeremy Zolan in Feb., 2006; Harold Moritz collection |
[var: Smoky Quartz] Harold Moritz collection | |
| Powell, Richard C. and Wolfgang Vogt. (1987), Cinque Quarry, A Suburban Site in Connecticut Makes Collecting a Cinch. Rock and Gem: (6): 36-39. |
[var: Smoky Quartz] Vener, Herm. (1987): Report on the Road Cut [Mclay Avenue] off Grannis St [Laurel Street] Just Past the Cinque Quarry. Triassic Valley Bulletin. | |
[var: Amethyst] Brace, John P. (1823), Miscellaneous Localities of Minerals. American Journal of Science: s.1, 6: 250-1. | |
Bill Barrett collection | |
| Weber, Marcelle H. and Earle C. Sullivan. (1995): Connecticut Mineral Locality Index. Rocks & Minerals (Connecticut Issue): 70(6): 407. |
| A. Berluti collection; Henderson, William A., Jr, and Michael Haritos. (1989), Amethyst Scepters, Salem, New London County, Connecticut. Rocks & Minerals: 64(6). |
| Zodac, Peter (1948), Diamond Ledge, West Stafford, Conn. Rocks & Minerals: 23: 611. |
| Ague, J. J. (1995): Deep Crustal Growth of Quartz, Kyanite and Garnet into Large-Aperature, fluid-filled fractures, northeastern Connecticut, USA. Journal of Metamorphic Geology: 13: 299-314.; Horowitz, Irving L. (2003): The Remarkable Quartz Crystals of West Willington, Tolland County, Connecticut. Rocks & Minerals: 78(4): 257-261. |
[var: Amethyst] Harold Moritz collection | |
| [var: Amethyst] Harold Moritz collection |
[var: Amethyst] Clark, Bill. (2001). Connecticut Quartz: Interesting Specimens from a former Collecting Site. Rock & Gem: 31(8). | |
| [var: Smoky Quartz] Wells, H. L. (1887), Bismutosphaerite from Willimantic and Portland. American Journal of Science: s. 3, 34: 271-4. |
| [var: Amethyst] Min Rec 36:3 pp 288-289 [www.johnbetts-fineminerals.com] |
| [var: Smoky Quartz] Ted Johnson Collection |
| T. Kennedy collection |
| [var: Rose Quartz] Barry Heath and Frank Perham; King, V. (ed.), 2009, Maine feldspar, Families, and Feuds. |
[var: Rose Quartz] King, V. and Foord, E., 1994, Mineralogy of Maine, King, V. Maine Feldspar, Families, and Feuds.; Cameron, Eugene N.; and others (1954) Pegmatite investigations, 1942-45, in New England. USGS Professional Paper 255. | |
| Rocks & Min.: 62: 443; King, V. and Foord, E., 1994, Mineralogy of Maine.; Mineral News (1993) 9:2 p. 8 |
| [var: Rose Quartz] Stan Perham personal communication, 1963. |
| [var: Rose Quartz] King, V. T., 2006, Minerals of Halls Ridge and Plumbago-Puzzle Mountain, Newry, ... Maine, Mineral News, v. 22(6): p. 1-3. |
[var: Rose Quartz] King, V. and Foord, E., 1994, Mineralogy of Maine, v. 1.; Mineralogical Record 22:382 | |
| King, V. T. and Foord, E. E., 1994, Mineralogy of Maine, Descriptive Mineralogy, volume 1, Maine Geological Survey, Augusta, Maine, USA, pp. 418 + 88 plates. "Maine Mineral Localites, 3rd Ed." by Thompson, W.B., et.al. , 1998 Mineralogical Record 22:382; Encar Roda-Robles, William Simmons, Alexander Falster, Alfonso Pesquera, Pedro-Pablo Gil-Crespo (2018) Paragenetic and compositional evolution of tourmaline from the Mt. Mica pegmatite (Maine, USA). in abstracts of the 22nd IMA Meeting Melbourne p 498; Myles M. Felch, William B. Simmons, Alexander U. Falster, and Karen L. Webber (2016) A large scale boundary layer texture in the Mt. Mica pegmatite, Paris, Oxford County, Maine. in Second Eugene E. Foord Pegmatite Symposium July 15-19, 2016 Colorado School of Mines campus, Golden, Colorado Hernández-Filiberto L, Roda-Robles E, Simmons WB, Webber KL. Garnet as Indicator of Pegmatite Evolution: The Case Study of Pegmatites from the Oxford Pegmatite Field (Maine, USA). Minerals. 2021; 11(8):802. https://doi.org/10.3390/min11080802 |
| [var: Rose Quartz] King, V. and Foord, E., 1994, Mineralogy of Maine, v. 1. |
| [var: Amethyst] [www.johnbetts-fineminerals.com]; Mineralogical Record (1990) 21:203-213 |
| [var: Amethyst] Mineralogical Record (1990) 21:203-213 |
| Edith Trebilcock |
| No reference listed |
| [Jasper] William Prescott (1852) Journal of the Essex County Natural History Society: containing various Communications to the Society pp 78-91 |
| [var: Amethyst] Harvard Museum of Natural History, no.119196; Mineralogical Record (1990) 21:203-213 |
Gleba, 1978. Massachusetts Mineral & Fossil Localities | |
| [var: Amethyst] Michael W. Kieron collection; Mineralogical Record (1990) 21:203-213 |
| [var: Amethyst] [www.johnbetts-fineminerals.com] |
| [Chalcedony var: Agate] Rosemeyer, T. 2011 New from the Keweenaw: Part 4 - Recent Mineral Finds in Michigan's Copper Country. Rocks & Minerals 86:205-227 |
Mineralogy of Michigan (2004) Heinrich & Robinson | |
| Mineralogy of Michigan (2004) Heinrich & Robinson |
| [Chalcedony var: Agate] Carl Dietrich |
| [Chalcedony var: Moss Agate] The River Runs North - the Story of Montana Moss Agate by Tom Harmon (author) |
| Ryan Sweeney Collection |
| [var: Amethyst] Rocks & Minerals 47:3 pp160-164; U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia. |
| [var: Amethyst] Rob Lavinsky Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie |
[var: Sceptre Quartz] Ref: Schlegel, J. (1999) Report to the Mineralogical Society of Southern California: Field Collected Quartz, v. Amethyst measuring 15x10cm; Crystal Tips #1, Hallelujah Mine, Petersen Mountain, Washoe County, Nevada; May 31st. | |
| Randy Lahey |
| [var: Pseudocubic Quartz] Tarr, W.A., Lonsdale, J.T. (1929) Pseudo-cubic quartz crystals from Artesia, New Mexico. American Mineralogist, 14, 50-53. |
| Min Rec 22:5 pp359-366 The Smoky Bear Quartz Claims Lincoln County New Mexico |
| Dana 7:I:592.; Econ Geol (1990) 85:182-196 |
| Econ Geol (1990) 85:182-196 |
| [var: Amethyst] www.grandfather.com/museum/amethyst.htm Genth,F.A.,1891,The Minerals Of North Carolina;USGS Bulletion No.74 |
| Samuel S. Gordon (1922) Mineralogy of Pennsylvania.; pg. 234 |
| [var: Amethyst] Miller, C. E. (1971) Rhode Island Minerals and Their Locations, O. D. Hermes, Ed., University of Rhode Island, Kingston |
| [var: Amethyst] Mineralogical Record (1990) 21:203-213 |
| [www.johnbetts-fineminerals.com]; Rocks & Minerals (1986) 61:264-275 |
| Miller, C. E. (1971) Rhode Island Minerals and Their Locations, O. D. Hermes, Ed., University of Rhode Island, Kingston; Rocks & Min.: 17:51; 20:463-464.; Rocks & Minerals (1986) 61:264-275; Rocks & Minerals (1986): 61: 286-289 |
| [var: Amethyst] [Rakovan et al, 1995 - "Amethyst on Milky Quartz from Hopkinton, Rhode Island",; Mineralogical Record (1990) 21:203-213; Rocks & Minerals (1986): 61: 247-250 Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie |
| Miller, C. E. (1971) Rhode Island Minerals and Their Locations, University of Rhode Island, Kingston |
| [var: Amethyst] [www.johnbetts-fineminerals.com] |
| [var: Rose Quartz] Rocks & Min.: 10:145; 16:360-363; 57:54. |
[var: Rose Quartz] R&M 75:3 pp 156-169 | |
| U.S. Geological Survey, 2005, Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.; Calkins, F. C.; Butler, B. S.; Heikes, V. C. (1943) Geology and ore deposits of the Cottonwood-American Fork area, Utah, with sections on history and production. USGS Professional Paper: 201 |
| Matthew Lambert |
| Huntting, M. (1956): Inventory of Washington Minerals, Part II, Metallic Minerals, Vol. 1, p. 113; Lasmanis, R. Et Al (1990): Metal Mines of Washington-Preliminary Report, p.14; Linda D. Gill, 2008; Collected at 1800 level |
| Min Record:20(5):390; Minerals of Washington, B. Cannon, 1975; Rocks and Minerals 66:6, p.469 |
| [var: Amethyst] UBC specimen |
| Eric He's Collection; Ray Claude (1995) Mineral Sites of King County, Washington: 27 |
| Cannon, B. (1975): Minerals of Washington, p.71 |
[var: Amethyst] Bob Jackson, mine owner; Rocks & Minerals (1991) 66:466-476 | |
Minerals of Washington, Bart Cannon, 1975; Rocks and Minerals 66:6, p.469 | |
Vietnam | |
| "Mario Lazzerini Denchi' Collection" |
Zambia | |
| [var: Citrine] Peter Beckwith collection |
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Las Vigas de Ramírez Municipality, Veracruz, Mexico