General Information:
Chemical Formula:
Mn++++5-x(Mn++,Fe+++)1+xO8(OH)6, x = 0,2
Composition:
(Molecular Weight = 559.85 gm)
Manganese 56.92 % Mn
Iron 2.00 % Fe
Hydrogen 1.08 % H
Oxygen 40.01 % O
Empirical Formula:
Mn4+4.8Mn2+Fe3+0.2O8OH6
Environment:
In the zone of supergene manganese oxides.
IMA Status:
Approved IMA 1976
Locality:
Janggun mine, Bonghwa, Korea.
Name Origin:
Named for the locality.
Physical Properties:
Cleavage:
[???] Indistinct
Color:
black.
Density:
3.59
Diaphaniety:
Opaque
Habits:
Colloform - Forming from a gel or colloidal mass., Dendritic - Branching "tree-like" growths of great complexity (e.g. pyrolusite)., Flakes - Flat, thin crystals or aggregates.
Hardness:
2-3 - Gypsum-Calcite
Luster:
Earthy (Dull)
Streak:
brownish black
More details...