Composition: Co3+O(OH)
Crystal System : Trig. Hex.
Colours: Black, steel-grey
Lustre : Metallic, resinous, greasy
Hardness (H) : 4.5
Specific Gravity (S.G) : 3.07-4.37


Rare. First and second oxidation zones.


  • Supergene
  • 1st Oxidation Zone
  • 2nd Oxidation Zone

Paragenetic and General Notes

Bright black botryoidal masses to several kilograms, and lustrous black coatings on calcite crystals (Pinch and Wilson, 1977).

Heterogenite may be confused with goethite.