Heterogenite
Mineral CoO(OH)
About it
Black, glossy botryoidal crusts and earthy masses, the main cobalt mineral of the Congolese copper belt. Often seen with pink cobaltoan calcite and green malachite from Katanga.
- Type
- Mineral
- Group
- Hydroxide
- Formula
- CoO(OH)
- Hardness (Mohs)
- 3–5
- Specific gravity
- 4.1–4.5
- Streak
- dark brown to black
- Lustre
- submetallic, metallic, dull
- Crystal system
- Trigonal
- Colours
- black, steel grey
- Transparency
- opaque
Typical values: real specimens vary. For more, see mindat.org.