Cobalt arsenic sulfide forming silver-white cubic crystals. Important cobalt ore with pyrite-like structure. Color: Silver-white with reddish tinge. Luster: Metallic. Streak: Grayish-black. Cleavage: Perfect cubic. Hardness: 5.5. Transparency: Opaque. Crystal system: Orthorhombic pseudo-cubic. Chemical formula: CoAsS. Specific gravity: 6.33. Formation: Forms in high-temperature hydrothermal veins and in contact metamorphic zones. Common geological settings: Sweden, Canada, Morocco, Democratic Republic of Congo; found in hydrothermal veins. Common look-alikes and related entries: Pyrite, Skutterudite, Arsenopyrite. Specimen safety: Keep this arsenic-bearing specimen intact. Do not cut, grind, polish, streak, lick, heat, or use acid on it. Avoid creating or breathing dust or fumes, wash your hands with soap and water after handling, and keep it away from food, children, and pets.
These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.
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GeoMiner
Last updated
2026-03-30T14:37:51.876511+00:00
Review status
Published; not independently peer-reviewed
IMA–CNMNC List of Mineral Names — International Mineralogical Association. Official mineral-name, nomenclature, and classification records.
Mineral ID Key — Mineralogical Society of America. Physical-property identification methods, repeat-testing guidance, and limitations.
Arsenic (inorganic compounds, as As) — CDC/NIOSH. Official occupational-hazard, exposure-route, symptom, and protective-equipment information for inorganic arsenic compounds.
Cobalt arsenic sulfide forming silver-white cubic crystals. Important cobalt ore with pyrite-like structure.
How can you identify Cobaltite?
Compare several properties rather than relying on colour alone. This entry records colour: Silver-white with reddish tinge; lustre: Metallic; streak: Grayish-black; Mohs hardness: 5.5; cleavage: Perfect cubic; crystal system: Orthorhombic pseudo-cubic; transparency: Opaque. Confirm an important identification with additional field tests or qualified laboratory work.
How does Cobaltite form?
Forms in high-temperature hydrothermal veins and in contact metamorphic zones.
Where is Cobaltite commonly found?
Sweden, Canada, Morocco, Democratic Republic of Congo; found in hydrothermal veins.
Is Cobaltite safe to handle?
Keep this arsenic-bearing specimen intact. Do not cut, grind, polish, streak, lick, heat, or use acid on it. Avoid creating or breathing dust or fumes, wash your hands with soap and water after handling, and keep it away from food, children, and pets. Avoid creating dust or using destructive tests on an unknown specimen, and follow site-specific safety procedures.
What is Cobaltite commonly confused with?
Cobaltite may be confused with Pyrite, Skutterudite, Arsenopyrite. Compare multiple diagnostic properties because colour and surface appearance can overlap.
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