Carrollite
Species
Uncommon · CuCo₂S₄
Copper cobalt sulfide, steel grey and tarnishing copper red or violet grey, in octahedral crystals up to 10 cm at Kambove and Kolwezi in Katanga. Named for Carroll County, Maryland. A cobalt mineral of the Central African Copperbelt copper ores, whose weathering is thought to yield heterogenite.
Identity
- Formula
- CuCo₂S₄
- Chemical class
- Sulfide
- Ore of
- Cobalt
Crystallography
- Crystal system
- Cubic
- Habits
- Octahedral, Massive, Granular
- Fracture
- Uneven
Physical properties
- Mohs hardness
- 5
- Density
- 4.7 g/cm³
- Luster
- Metallic
- Colors
- steel gray, pale gray
- Transparency
- Opaque
Geology
- Origins
- Hydrothermal
- Host rocks
- Granite
- Associated minerals
- Tetrahedrite, Chalcopyrite, Bornite, Chalcocite, Pyrrhotite, Pyrite, Sphalerite
- Found in
- Hydrothermal vein (lode)
- Geography
- DR Congo (Kambove, Kolwezi, Katanga), Zambia (Kitwe), USA (Patapsco mine, Carroll County, Maryland), Germany (Siegerland), Sweden (Gladhammar), Namibia (Tsumeb)
Classification
- Rarity
- Uncommon
- 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, Carrollite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- Carrollite. Wikipedia.
- Heterogenite. Wikipedia.
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