crystals of erythrite, cristals of cobaltkoritnigite : Shaft 1, Bou Azer (Bou Azzer), Bou Azer District (Bou Azzer District), Tazenakht, Ouarzazate Province, Souss-Massa-Draâ Region, Morocco — Photo: Parent Géry · CC BY-SA 3.0
Cobaltkoritnigite
Cobaltkoritnigite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Co(AsO₃OH)·H₂O.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Koritnigite structural group.
Key properties: Mohs hardness 2; specific gravity 3.46; White streak; Vitreous luster; optically biaxial.
IMA symbol Ckor, IMA status: approved, named in 1980.
A weathering product of glaucodot (Saxony, Germany); altering from cobaltite (Bauhaus district, Germany).
It is found associated with Erythrite–köttigite, sphaerocobaltite, pitticite, glaucodot, löllingite–safflorite, arsenopyrite, quartz (Saxony, Germany); erythrite, cobaltite, calcite.
The name refers to its relation to koritnigite and high cobalt content.