Cooperite
Species
Rare · PtS
Platinum sulfide with palladium and nickel, steel grey, in small grains: a significant platinum ore of layered ultramafic and mafic intrusions. Described in 1928 from the Merensky Reef of the Bushveld Complex, South Africa, where it is mined for platinum and palladium, and named for the metallurgist Richard A. Cooper, who first characterised it.
Identity
Crystallography
- Crystal system
- Tetragonal
- Habits
- Granular, Rounded
- Fracture
- Conchoidal
Physical properties
- Mohs hardness
- 4.5
- Density
- 9.5 g/cm³
- Luster
- Metallic
- Colors
- steel gray
- Transparency
- Opaque
Geology
- Origins
- Igneous, Sedimentary
- Host rocks
- Volcanic rock, Ultramafic rock (peridotite, serpentinite), River gravels and sands
- Associated minerals
- Sperrylite, Platinum, Chalcopyrite, Bornite, Pentlandite, Pyrrhotite, Pyrite, Chromite
- Found in
- Placer deposit
- Geography
- South Africa (Rustenburg, Merensky Reef, Bushveld), USA (Stillwater, Montana), Russia (Norilsk; Konder massif), Canada (Lac des Iles, Ontario), Sierra Leone (Freetown complex)
Classification
- Rarity
- Rare
- Gem quality
- No
Sources
- M. Pasero and others, IMA Commission on New Minerals, Nomenclature and Classification, The New IMA List of Minerals, updated September 2026. International Mineralogical Association (CNMNC), 2026.
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Cooperite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- Cooperite (mineral). Wikipedia.
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