General Information:
Chemical Formula:
(Fe++,Mn)6(Fe+++,Al)3Si6O20(OH)5
Composition:
(Molecular Weight = 1,052.69 gm)
Manganese 10.44 % Mn
Aluminum 1.92 % Al
Iron 33.16 % Fe
Silicon 16.01 % Si
Hydrogen 0.48 % H
Oxygen 38.00 % O
Empirical Formula:
Fe2+4Mn2+2Fe3+2.25Al0.75Si6O20(OH)5
IMA Status:
Approved IMA 1966
Locality:
Laytonville quarry, 5 miles south of Laytonville, Mendocino Co. California.
Physical Properties:
Cleavage:
[110] Good
Color:
black.
Density:
3.837
Diaphaniety:
Transparent to Subopaque
Hardness:
6 - Orthoclase
Streak:
black gray
More details...