Chlorocalcite

Chlorocalcite
General
Category Halide mineral
Formula
(repeating unit)
KCaCl3
Strunz classification 3.AA.40
Crystal system Orthorhombic
Crystal class Dipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space group Pnma (from synthetic crystals)
Unit cell a = 7.35 Å, b = 10.44 Å,
c = 7.25 Å; Z = 4
Identification
Formula mass 185.54 g/mol
Color White, tinged violet
Crystal habit Prismatic or tabular cube-like crystals, pseudo cubic
Cleavage Perfect on {001}, good on {010} and {100}
Mohs scale hardness 2.5-3
Diaphaneity Transparent to semi-transparent
Density 2.16 calculated
Optical properties Biaxial (–)
Refractive index ~1.52
Birefringence weak
Solubility In water
Other characteristics Deliquescent
References [1][2][3][4]

Chlorocalcite is a rare potassium calcium chloride evaporite mineral with formula: KCaCl3. It is found in active volcanic fumaroles.

It was first described in 1872 for an occurrence on Mount Vesuvius and given the name for its calcium content previous to discovering that it also contained potassium.[2][3] It has also been reported from the Desdemona Mine, Peine, Lower Saxony, Germany.[2]

References

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