Calclacite

Calclacite is a mineral and an organic compound. Its name references the components, which are calcium ions (Ca²⁺), chloride (Cl⁻) and acetate CH₃COO⁻.

Calclacite
General
Category	Minerals
Formula	Ca(CH3COO)Cl·5H2O
IMA symbol	Calc[1]
Crystal system	Monoclinic
Identification
Color	White
Mohs scale hardness	1.5
Luster	Silky
Diaphaneity	Translucent
Specific gravity	1.5
Optical properties	Biaxial (+)
Refractive index	nα = 1.468 nβ = 1.484 nγ = 1.515
Birefringence	δ = 0.047
2V angle	Measured: 80°, Calculated: 74°
Dispersion	Relatively feeble
References	[2]

Characteristics

Calclacite is an organic compound with chemical formula Ca(CH₃COO)Cl·5H₂O. It forms crystals in the monoclinic system, with silky hairlike efflorescences up to 4 cm long.

According to the Nickel–Strunz classification, calclacite is an organic acid salt and occurs with formicaite (calcium formate), acetamide, dashkovaite (magnesium acetate), paceite (calcium copper acetate) and hoganite (copper acetate).^[2] It is white and its hardness on the Mohs scale is 1.5.

Formation

Calclacite is formed on samples of rocks, fossils, and on fragments of ceramics, by the action of acetic acid produced from the oak of the storage cabinets.^[2]