Article · Wikipedia archive · Last revised Jul 6, 2026

Chlorocalcite

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

Last revised
Jul 6, 2026
Read time
≈ 1 min
Length
146 w
Citations
8
Source
Chlorocalcite
General
CategoryHalide mineral
FormulaKCaCl3
IMA symbolCcal1
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
References2345

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

References

References