Magnesiochromite
Mineral MgCr2O4
About it
The magnesium-rich partner of chromite, black with a dark streak, in serpentinites and kimberlites. Much chromite ore is a mix of the two; it is also found as tiny inclusions in diamonds.
- Type
- Mineral
- Group
- Oxide, spinel group
- Formula
- MgCr2O4
- Hardness (Mohs)
- 5.5
- Specific gravity
- 4.2–4.4
- Streak
- brown to dark grey
- Lustre
- metallic, submetallic
- Crystal system
- Isometric (cubic)
- Colours
- black
- Transparency
- opaque
- Cleavage and fracture
- none; uneven fracture
Typical values: real specimens vary. For more, see mindat.org.