Ullmannite | |
---|---|
General | |
Category | Sulfide mineral |
Formula (repeating unit) | NiSbS |
IMA symbol | Ull[1] |
Strunz classification | 2.EB.25 |
Crystal system | Cubic |
Crystal class | Tetartoidal (23) H-M symbol: (23) |
Space group | P213 |
Unit cell | a = 5.91(2) Å; Z = 4 |
Identification | |
Color | Steel-gray to tin white |
Twinning | Penetration twins about [110] |
Cleavage | Perfect on {001} |
Fracture | Uneven |
Tenacity | Brittle |
Mohs scale hardness | 5–5.5 |
Luster | metallic |
Diaphaneity | Opaque |
Specific gravity | 6.65–6.85 |
References | [2][3][4] |
Ullmannite or Nickel glance (trivial name) is a nickel antimony sulfide mineral with formula: NiSbS. Considerable substitution occurs with cobalt and iron in the nickel site along with bismuth and arsenic in the antimony site. A solid solution series exists with the high cobalt willyamite.