13 Photos
Cobaltite
Chemical Formula	CoAsS
Species	Sulfides
Crystal System	Orthorhombic
Mohs Scale	5
Specific Gravity	6.335
Color	Reddish silver white, Purple steel gray to black
Streak	Grayish-black
Luster	Metallic
Diaphaneity	Opaque
Cleavage	PerfectPerfect on
Fracture	Irregular/Uneven
Crystal Habit：Granular to massive, rarely as striated crystals
Geological Setting：High temperature hydrothermal deposits, veins in contact metamorphic rocks.

Cobaltite is a sulfosalt mineral composed of cobalt, arsenic and sulfur, CoAsS. It contains up to 10 percent iron and variable amounts of nickel. Structurally it resembles pyrite (FeS₂) with one of the sulfur atoms replaced by an arsenic atom.

Although rare it is mined as a significant source of the strategically important metal cobalt. Secondary weathering incrustations of erythrite, hydrated cobalt arsenate, are common.

The name is from the German, Kobold, "underground spirit" in allusion to the "refusal" of cobaltiferous ores to smelt as they are expected to.

It occurs in high temperature hydrothermal deposits and contact metamorphic rocks. It occurs in association with magnetite, sphalerite, chalcopyrite, skutterudite, allanite, zoisite, scapolite, titanite, calcite along with numerous other Co–Ni sulfides and arsenides. It was described as early as 1832.

It is found chiefly in Sweden, Norway, Germany, Cornwall, England, Canada, Australia, Democratic Republic of the Congo and Morocco.