Ferberite
Mineral FeWO4
About it
The iron-rich wolframite: black, very heavy, and weakly magnetic, with a dark streak. Bladed crystals come from Panasqueira in Portugal and Bolivia, and the Boulder County tungsten district of Colorado mined it.
- Type
- Mineral
- Group
- Tungstate, wolframite group
- Formula
- FeWO4
- Hardness (Mohs)
- 4–4.5
- Specific gravity
- 7.4–7.6
- Streak
- brownish black to black
- Lustre
- submetallic, metallic
- Crystal system
- Monoclinic
- Colours
- black
- Transparency
- opaque
- Cleavage and fracture
- perfect in one direction; uneven fracture
- Magnetic
- Weakly
Typical values: real specimens vary. For more, see mindat.org.