Zulifigar is a legendary sword that is celebrated among both doctrines (Sunni and Shiite). However, in explanation of the sword's history the Shiite version appear more "mythical", being in line with their believe of Emam Ali's and his house divinity....
Its called "Zulfigar", meaning: the one with "Vertebrae"....such vertebrae is called "Faqra" "الفقرة" in Arabic and so the plural/adjective form is Zulfigar...
What appears in some sources is that its a Straight sword that contain that vertebraes......The other sword famous of being of two blades on the tip is just another sword of Emam Ali...
According to Sunni, the Prophet Mohammed first obtained the sword after victory at the Battle of Badir and he gifted it to Emam Ali, because Emam Ali broke 3 swords during battle....Sunnis don't elevate the origin or the significance of the sword to the level of Angel Gabriel or any other mythical story......Emam Ali actually had many swords, and not only Zulfigar was gifted to him by the Prophet....
According to Shiite, the sword's source is from Angel Gabriel and itself a descendent from Adam for which only Prophets should carry it....
To my memory, fragments of the sword survive in the Topkapi palace....
In Arab history, many swords gained great fame along with Emam Ali's Zulfigar.....a very famous one is "Al-Sumsaam", which is said to survive since pre-Islam until Abbassid age, and were called by that name to mean: the sword that cannot bend or break.....Caliph Haroun tried it on 10 of the finest Indian blades and Al-Sumsaam broke them all....
I've attached a cover of a book on the Prophet's swords, showing Zulfigar...