breithauptite

{{infobox mineral | name = Breithauptite | category = Antimonide mineral | boxwidth = | boxbgcolor = | image = Breithauptite-229669.jpg | imagesize = 260px | alt = | caption = Breithauptite on calcite from the Samson Mine, St Andreasberg, Harz Mountains, Lower Saxony, Germany (Field of view 17 mm) | formula = nickel antimonide (NiSb) | IMAsymbol=Bhp | molweight = | strunz = 2.CC.05 | dana = | system = Hexagonal | class = Dihexagonal dipyramidal (6/mmm) H-M symbol: (6/m 2/m 2/m) | symmetry = P63/mmc | unit cell = a = 3.946 Å, c = 5.148 Å, Z = 2 | color = Pale copper-red, may be with violet tint | colour = | habit = Crystals rare, thin tabular or needlelike, to 1 mm; arborescent, disseminated, massive | twinning = Twin plane {101} | cleavage = None | fracture = Subconchoidal to uneven | tenacity = Brittle | mohs = 5.5 | luster = Metallic | streak = Reddish brown | diaphaneity = Opaque | gravity = 7.591–8.23 measured; 8.629 calculated | density = | polish = | opticalprop = | refractive = | birefringence = | pleochroism = Very distinct | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence= | absorption = | melt = | fusibility = | diagnostic = | solubility = | other = | alteration = | references = }} Breithauptite is a nickel antimonide mineral with the simple formula NiSb. Breithauptite is a metallic opaque copper-red mineral crystallizing in the hexagonal - dihexagonal dipyramidal crystal system. It is typically massive to reniform in habit, but is observed as tabular crystals. It has a Mohs hardness of 3.5 to 4 and a specific gravity of 8.23.

It occurs in hydrothermal calcite veins associated with cobalt–nickel–silver ores.