Cryolite
Cryolite is a halide mineral recognized among collectors for its crystal form and distribution.
About Cryoliteextended article
Cryolite is a sodium aluminium fluoride (Na3AlF6), historically important as the flux that made aluminium smelting possible. Its name, from the Greek for 'frost stone', reflects its icy white appearance and an unusually low refractive index that lets crushed crystals nearly disappear when placed in water.
Properties
Cryolite is monoclinic but forms pseudo-cubic crystals and granular masses; it is soft (2.5–3) and colourless to white, sometimes tinted by inclusions. Most museum specimens come from a single legendary deposit.
Occurrence
The great commercial source was Ivigtut (Ivittuut) in south-west Greenland, a massive cryolite body that was mined out in the twentieth century, after which the smelting industry switched to synthetic cryolite. Minor occurrences are known at Miask in the Urals and at Pikes Peak, Colorado. Well-crystallised natural cryolite is now scarce and collectable.
About Cryolite
Cryolite is classified as a halide mineral in the cryolite group and has the chemical formula Na3AlF6. It crystallizes in the monoclinic system and is relatively soft, requiring careful handling.
Identification & care
Specimens usually show pseudocubic crystals; massive. Its color is typically colorless, snow-white and grayish. The luster is vitreous to waxy, the streak is white, and specimens range from transparent to translucent; appears invisible in water. The fracture is uneven, which is one of its key identifying features.
Collector context
Collector notes
For collectors, Cryolite is a benchmark crystalline species.
Frequently asked questions
What is Cryolite?
Cryolite is a halide mineral recognized among collectors for its crystal form and distribution.
What crystal system does Cryolite belong to?
Cryolite crystallises in the Monoclinic crystal system.
References & databases
Mindat.org is the world’s largest open mineralogy database. Our descriptions are written independently and fact-checked.