Formula: Cu6[AsO3(OH)]6.8H2O
Specific gravity: 3.123 calculated
Hardness: 2
Streak: White
Colour: Greenish-blue, occasionally with a grey tint
Luminescence: Not fluorescent under long wave or short wave UV
Solubility: Insoluble in water. Soluble in 10% hydrochloric acid, at room temperature.

Hydrothermal environments

Krupičkaite is a new mineral, approved in 2020 and to date (June 2022) reported only from the type locality.


At the type locality, the Geister vein, Rovnost mine, Jáchymov, Karlovy Vary District, Karlovy Vary Region, Czech Republic, krupičkaite occurred as rounded or grape-like aggregates, greenish-blue in colour, to 4 mm in size, sitting at the surface of the supergene crusts. The aggregates are composed of hundreds of microcrystals that are not larger than a few microns. Associated minerals include veselovskýite, uraninite, tennantite subgroup minerals, quartz, pradetite, lindackerite, klajite, hloušekite, galena, chalcopyrite, chalcocite, bornite and babánekite (Mindat).
Krupičkaite was found in an old ore-stope from near surface mining work. The mine was worked for uranium and radium for glass staining and for the Soviet nuclear weapons program. The structure of krupičkaite is closely related to geminite, and to slavkovite (AM 107.319-320).

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