General Information:
Chemical Formula:
Cu+Mn++14Fe+++(As+++O3)5(SiO4)2(As+++++O4)(OH)6
Composition:
(Molecular Weight = 1,928.25 gm)
Manganese 39.89 % Mn
Iron 2.90 % Fe
Copper 3.30 % Cu
Silicon 2.91 % Si
Arsenic 23.31 % As
Hydrogen 0.31 % H
Oxygen 27.38 % O
Empirical Formula:
CuMn2+14Fe3+(AsO3)5(SiO4)2(AsO4)(OH)6
Locality:
Langbanshyttan, Vermland, Sweden.
Physical Properties:
Cleavage:
[001] Perfect
Color:
bronze or black.
Density:
4.2
Diaphaniety:
Translucent to subtranslucent to opaque
Habits:
Foliated - Two dimensional platy forms., ,
Hardness:
3-4 - Calcite-Fluorite
Luster:
Vitreous (Glassy)
More details...