General Information:
Chemical Formula:
(Ba,H2O)2Mn5O10
Composition:
(Molecular Weight = 649.68 gm)
Barium 31.71 % Ba
Manganese 42.28 % Mn
Hydrogen 0.16 % H
Oxygen 25.86 % O
Empirical Formula:
Ba1.5(H2O)0.5Mn3+5O10
Environment:
General term for hard, black Mn oxides. Romanechite is one of the most common species.
IMA Status:
Not IMA Approved
Locality:
Common world wide.
Name Origin:
From the Greek psilos - "smooth" and melas - "black."
Physical Properties:
Cleavage:
None
Color:
iron black or dark steel gray.
Density:
4.4 - 4.7, Average = 4.55
Diaphaniety:
Opaque
Habits:
Botryoidal - "Grape-like" rounded forms (e.g.. malachite)., Reniform - "Kidney like" in shape (e.g.. hematite)., Mammillary - Larger "breast-like" rounded forms resembling botryoidal (e.g. malachite).
Hardness:
5-6 - Between Apatite and Orthoclase
Luminescence:
None.
Luster:
Sub Metallic
Streak:
brownish black
More details...