Laurite | |
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General | |
Category | Sulfide mineral |
Formula (repeating unit) | RuS2 |
Strunz classification | 2.EB.05a |
Crystal system | Cubic |
Crystal class | Diploidal (m3) H-M symbol: (P 2/m 3) |
Space group | Pa3 |
Unit cell | a = 5.61 Å; Z = 4 |
Structure | |
Crystal structure of Laurite S Ru | |
Identification | |
Color | Iron-black; white to gray or bluish in polished section |
Crystal habit | As octahedral, cubic, and pyritohedral crystals or as rounded grains and inclusions |
Cleavage | Perfect on {111} |
Fracture | Subconchoidal |
Tenacity | Brittle |
Mohs scale hardness | 7.5 |
Luster | Metallic |
Streak | Dark gray |
Diaphaneity | Opaque |
Specific gravity | 6.43 |
Density | 6.43 g/cm3 (Measured) 6.39 g/cm3 (Calculated) |
Optical properties | Isotropic and opaque |
References | [1][2][3] |
Laurite is an opaque black, metallic ruthenium sulfide mineral with formula: RuS2. It crystallizes in the isometric system. It is in the pyrite structural group. Though it's been found in many localities worldwide, it is extremely rare.
Laurite has a Mohs hardness of 7.5 and a specific gravity of 6.43. It can contain osmium, rhodium, iridium, and iron substituting for the ruthenium.[2] The sulfur is present as the disulfide ion, S2−2, so the ruthenium is in the Ru(II) oxidation state.[4]