Hollandite
Mineral BaMn8O16
About it
Black to silver-grey prisms and fibrous masses of barium manganese oxide, hard to tell from cryptomelane by eye. Named for Sir Thomas Holland of the Geological Survey of India, where it was first described.
- Type
- Mineral
- Group
- Oxide, hollandite group
- Formula
- BaMn8O16
- Hardness (Mohs)
- 4–6
- Specific gravity
- 4.7–5
- Streak
- black
- Lustre
- submetallic, dull
- Crystal system
- Monoclinic
- Colours
- black, silver grey
- Transparency
- opaque
Typical values: real specimens vary. For more, see mindat.org.