Zharchikhite

 Zharchikhite is a halide mineral, a hydroxyl fluoride of aluminium; formula AlF(OH)2. It forms colourless, transparent crystals. Discovered in 1968, it is named after its original locality, the Zharchinskoya Deposit, which is in Buryatia, Russia.

Zharchikhite
General
CategoryHalide mineral
Formula
(repeating unit)
AlF(OH)2
Strunz classification3.AC.05
Crystal systemMonoclinic, pseudo-orthorhombic
Identification
ColourColorless
Crystal habitElongated prismatic cryatals, massive, drusy coatings
CleavagePerfect (010)
TenacityVery brittle
Mohs scale hardness4.5
LusterVitreous
DiaphaneityTransparent
Specific gravity2.81
Optical propertiesBiaxial (-)
Refractive indexnα = 1.532 nβ = 1.552 nγ = 1.567
Birefringenceδ = 0.035
2V angle80° (calculated)
References

This article uses material from the Wikipedia article
 Metasyntactic variable, which is released under the 
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