Vermilion Mine, Sudbury Ontario, Canada — Photo: Pacific Museum of Earth from Canada · CC BY-SA 2.0
Violarite
A violet-gray nickel-iron thiospinel — the supergene replacement of pentlandite in nickel deposits.
Intro adapted from Wikipedia (CC BY-SA).
Violarite is an IMA-recognized mineral species in the sulfide class, with the chemical formula FeNi₂S₄.
It crystallizes in the cubic crystal system (space group Fd-3m). It is a member of the Spinel structural group.
Key properties: Mohs hardness 4.5–5.5; specific gravity 4.79; gray-black streak; Metallic. R: (400) 39.0, (420) 39.6, (440) 40.2, (460) 40.6, (480) 41.0, (500) 41.4, (520) 41.9, (540) 42.5 luster.
IMA symbol Vio, grandfathered status — known before the IMA’s founding, named in 1889.
Of hydrothermal origin, with other sulfides.
It is found associated with Pyrrhotite, millerite, chalcopyrite, pentlandite.
The name comes from the Latin for violet, its color on a polished surface.