Columbite-(Mn)
Mineral MnNb2O6
Also called Manganocolumbite
About it
The manganese-rich partner of columbite-(Fe), often redder brown and translucent at thin edges. Found in lithium-rich pegmatites in Brazil, Madagascar, Afghanistan, and Maine.
- Type
- Mineral
- Group
- Oxide, columbite group
- Formula
- MnNb2O6
- Hardness (Mohs)
- 6
- Specific gravity
- 5.3–6.6
- Streak
- reddish black to dark brown
- Lustre
- submetallic, resinous
- Crystal system
- Orthorhombic
- Colours
- black, brownish black, reddish brown
- Transparency
- opaque, translucent
- Cleavage and fracture
- distinct in one direction; subconchoidal to uneven fracture
Typical values: real specimens vary. For more, see mindat.org.