Manganosite
Mineral MnO
About it
Emerald-green grains and small octahedrons in calcite that turn black on exposure. Known from Långban, Sweden, and Franklin, New Jersey.
- Type
- Mineral
- Group
- Oxide, periclase group
- Formula
- MnO
- Hardness (Mohs)
- 5–6
- Specific gravity
- 5.18–5.37
- Streak
- brown
- Lustre
- vitreous (glassy), adamantine (diamond-like)
- Crystal system
- Isometric (cubic)
- Colours
- emerald green, darkening to black
- Transparency
- transparent, translucent
- Cleavage and fracture
- good cubic
Typical values: real specimens vary. For more, see mindat.org.