Chlorocalcite
General
CategoryHalide mineral
Formula
(repeating unit)
KCaCl3
IMA symbolCcal[1]
Strunz classification3.AA.40
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupPnma (from synthetic crystals)
Unit cella = 7.35 Å, b = 10.44 Å,
c = 7.25 Å; Z = 4
Identification
Formula mass185.54 g/mol
ColorWhite, tinged violet
Crystal habitPrismatic or tabular cube-like crystals, pseudo cubic
CleavagePerfect on {001}, good on {010} and {100}
Mohs scale hardness2.5-3
DiaphaneityTransparent to semi-transparent
Density2.16 calculated
Optical propertiesBiaxial (–)
Refractive index~1.52
Birefringenceweak
SolubilityIn water
Other characteristicsDeliquescent
References[2][3][4][5]

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.[3][4] It has also been reported from the Desdemona Mine, Peine, Lower Saxony, Germany.[3]

References