3mm large cubic crystal of cobaltite from locality Varuträsk in Sweden... historical find from 1988 — Photo: GeologMax · CC BY-SA 4.0
Cobaltite
Also known as: Cobalt glance.
Cobalt arsenic sulfide — an important cobalt ore structurally related to pyrite and namesake of the cobaltite group.
Intro adapted from Wikipedia (CC BY-SA).
Cobaltite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula CoAsS.
It crystallizes in the orthorhombic crystal system (space group Pca2_1). It is a member of the Cobaltite structural group.
Key properties: Mohs hardness 5.5; specific gravity 6.33; typically gray or white; Grayish black streak; metallic luster.
IMA symbol Cbt, grandfathered status — known before the IMA’s founding, named in 1832.
Found in high-temperature hydrothermal deposits, as disseminations, and as veins in contact metamorphosed rocks.
It is found associated with Magnetite, sphalerite, chalcopyrite, skutterudite, allanite, zoisite, scapolite, titanite, calcite (Tunaberg, Sweden).
In allusion to the elemental composition.
Collections: Metals & Native Elements, Collector Favorites.