Cryolite Value, Price, and Jewelry Information


Cryolite
Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0], via Wikimedia Commons

Cut cryolite is somewhat translucent, and has a "sleepy" look. The cuttable material has a very low birefringence, is colorless, and very soft—not exactly an exciting-looking gem. However, there are very few cut stones in existence because of the extreme scarcity of suitable rough. In addition, cryolite is only found abundantly at one locality (Ivigtut).

Cryolite Value

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Cryolite Information

DataValue
NameCryolite
Crystallography Monoclinic. Crystals cuboidal and prismatic; usually massive.
Colors Colorless, white, brownish, reddish; rarely gray to black.
Luster Vitreous to greasy.
Fracture Uneven. Brittle.
Hardness 2.5
Specific Gravity 2.97
Birefringence 0.001; almost isotropic.
Cleavage None.
Dispersion 0.024 (approximately)
Stone SizesLarge cabochons could be cut from the abundant material in Greenland. Facetable material is quite rare, however, and only tiny gems can be obtained.
Luminescence None observed
Spectral Not diagnostic
FormulaNa3AlF6.
Pleochroism None

Optics:  a = 1.338; β= 1.338; γ = 1.339.

Biaxial (+), 2V= 43°.

Occurrence: Occurs in alkalic rocks at Ivigtut, Greenland.

Also Spain; USSR; Colorado (small amounts).

Comments: Cut cryolite is somewhat translucent, and has a “sleepy” look. The cuttable material has a very low birefringence, is colorless, and very soft—not exactly an exciting-looking gem. However, there are very few cut stones in existence because of the extreme scarcity of suitable rough. In addition, cryolite is only found abundantly at one locality (Ivigtut).

Name: From the Greek kryos (frost) and lithos (stone), hence ice-stone, in allusion to its appearance.