Thomsenolite

Thomsenolite

Thomsenolite (obelisks) and some pseudocubic ralstonite (picture center)
General
Category Halide minerals
Formula
(repeating unit)
NaCaAlF6·H2O
Strunz classification 3.CB.40
Crystal system Monoclinic
Identification
Colour Colourless, white, pale lilac; brownish or reddish tinted due to staining; colourless in transmitted light.
Crystal symmetry Monoclinic - prismatic
H-M symbol (2/m)
Space group P21/b
Cleavage Perfect
On {001}; {110} distinct.
Fracture Irregular/ uneven
Tenacity Brittle
Mohs scale hardness 2
Lustre Vitreous, pearly
Streak White
Diaphaneity Transparent, translucent
Density 2.981 g/cm3

Thomsenolite is a mineral with formula: NaCaAlF6·H2O. It is an alteration product of cryolite.[1]

It was discovered in 1868 in Ivigtut, Greenland and named for Hans Peter Jorgen Julius Thomsen (1826–1909).[2]

References


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