Olivenite (Cu₂(AsO₄)(OH)) is a copper arsenate forming olive-green to dark-green prismatic and acicular crystals — its name from the diagnostic olive color. Forms in oxidized cap zones of copper-arsenic deposits. Cornwall (England) is the historical type-area; Tsumeb (Namibia) yields modern collector specimens.
Key Facts
- Mohs hardness 3.
- Monoclinic; prismatic and acicular habit.
- Diagnostic olive-green color from Cu²⁺ + As bond.
- Forms in oxidized Cu-As deposits with malachite, azurite, mottramite.
- Toxic — soluble arsenate component.
Notable Localities
Cornwall (England) is the historical type-area. Tsumeb (Namibia) and Cap Garonne (France) supply modern collector material.
Found at these Localities
- Cornwall Mining District (康沃尔矿区)
- Tsumeb Mine (楚梅布矿)
