Magnesioferrite
Mineral MgFe2O4
About it
Black, strongly magnetic octahedrons much like magnetite but with a dark red streak, formed in volcanic fumaroles and burnt coal seams. Known from Vesuvius, Italy, and the Eifel, Germany.
- Type
- Mineral
- Group
- Oxide, spinel group
- Formula
- MgFe2O4
- Hardness (Mohs)
- 6–6.5
- Specific gravity
- 4.5–4.7
- Streak
- dark red
- Lustre
- metallic, submetallic
- Crystal system
- Isometric (cubic)
- Colours
- black, brownish black
- Transparency
- opaque
- Cleavage and fracture
- none; uneven to subconchoidal fracture
- Magnetic
- Strongly
Typical values: real specimens vary. For more, see mindat.org.