General Information:
Chemical Formula:
Bi2Fe+++(Cu,Fe++)(O,OH)2(OH)2(AsO4)2
Composition:
(Molecular Weight = 879.78 gm)
Iron 7.93 % Fe
Copper 5.42 % Cu
Bismuth 47.51 % Bi
Arsenic 17.03 % As
Hydrogen 0.29 % H
Oxygen 21.82 % O
Empirical Formula:
Bi2Fe3+Cu0.75Fe2+0.25O1.5(OH)2.5(AsO4)2
Environment:
In a silicified barite vein.
IMA Status:
Approved IMA 1993
Locality:
In a quarry near the Borstein cliff, about 1 km east of the town of Reichenbach, Odenwald, Hesse, Germany.
Name Origin:
For Dr. Olaf Medenbach (1949-) of the University of Bochum, Germany.
Physical Properties:
Cleavage:
None
Color:
yellow or brownish yellow.
Density:
5.9
Diaphaniety:
Transparent to translucent
Habits:
Crystalline - Fine - Occurs as well-formed fine sized crystals., Tabular - Form dimensions are thin in one direction.,
Hardness:
4.5 - Between Fluorite and Apatite
Luminescence:
Non-fluorescent.
Luster:
Vitreous - Adamantine
Streak:
light yellow
More details...