Pyrochroite
Mineral Mn(OH)2
About it
Pale, pearly plates and veinlets that darken to brown and black in air as the manganese oxidizes. Known from Franklin, New Jersey, and Långban, Sweden.
- Type
- Mineral
- Group
- Hydroxide, brucite group
- Formula
- Mn(OH)2
- Hardness (Mohs)
- 2.5–3
- Specific gravity
- 3.25–3.26
- Streak
- white
- Lustre
- vitreous (glassy), pearly
- Crystal system
- Trigonal
- Colours
- white, pale green, pale blue, darkening to brown and black
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect basal
Typical values: real specimens vary. For more, see mindat.org.