Cobaltite - Encyclopedia

    Class : Sulfides and sulfosalts
    Subclass : Sulfides
    Crystal system : Orthorhombic
    Chemistry : CoAsS
    Rarity : Uncommon

Cobaltite is probably the most common of the cobalt minerals. It is found associated with other arsenides or sulfides of nickel and cobalt in high temperature hydrothermal mineralizations (veins, pyrometasomatic deposits, etc...). Appreciable quantities of nickel and especially iron can replace cobalt. Its name is linked to its chemical composition. The crystals are very common : usually isometric and with striated faces, they are often pseudocubic, pseudo-octahedral, pentagonal pseudododecahedral and of mixed shapes ; rarely exceeding one centimeter. Cobaltite can also be massive, grainy or compact. Its color ranges from silver white with pink highlights to metallic gray with a purplish tint. Cobaltite was once a major source of cobalt, less popular today.

Main photo : Cobaltite from Håkansboda, Bergslagen mining district, Sweden © Kristalle

Twins are known around [111] and with {011} and {111} as composition planes.

No fake identified for this mineral species.