This 8 cm wide sample is almost all nickeline. Nickeline, sometimes called niccolite, is a nickel arsenide mineral having formula NiAs. An important nickel ore — Photo: Darla Sondrol · CC0
Nickeline
Also known as: Niccolite, Nickeline, Arsenical nickel.
Nickel arsenide — 'niccolite' — a copper-red metallic mineral of nickel-vein deposits.
Intro adapted from Wikipedia (CC BY-SA).
Nickeline is an IMA-recognized mineral species in the sulfide class, with the chemical formula NiAs.
It crystallizes in the hexagonal crystal system (space group P6_3/mmc). It is a member of the Nickeline structural group.
Key properties: Mohs hardness 5–5.5; specific gravity 7.784; typically pink or gray; Pale brownish black streak; Metallic luster.
IMA symbol Nc, IMA status: approved, named in 1832.
A minor component of Ni–Cu ores in high-temperature hydrothermal veins; massive and in disseminations in peridotite and norite.
It is found associated with Skutterudite–nickel-skutterudite, safflorite, rammelsbergite, gersdorffite, maucherite, breithauptite, michenerite, bismuth, bismuthinite.
The name comes from the German kupfernickel, or Devil’s copper, as the mineral was believed to contain copper but yielded none.
Collections: Metals & Native Elements, Collector Favorites.