White massive cryolithionite from Ivigtut, Ivittuut, Arsuk Fjord, Sermersooq, Greenland. — Photo: David Hospital · CC BY-SA 4.0
Cryolithionite
Cryolithionite is an IMA-recognized mineral species in the halide class, with the chemical formula Na₃Al₂(LiF₄)₃.
It crystallizes in the cubic crystal system (space group Ia3d). It is a member of the Garnet structural group.
Key properties: Mohs hardness 2.5–3; specific gravity 2.77; Vitreous luster.
IMA symbol Cyln, grandfathered status — known before the IMA’s founding, named in 1904.
Found in some granite pegmatites.
It is found associated with Cryolite, quartz, fluorite, siderite (Ivigtut, Greenland); cryolite, chiolite, pachnolite, thomsenolite, ralstonite, prosopite (Miass, Russia).
The name refers to its similarity to CRYOlite and high LITHIum content.