General Information:
Chemical Formula:(Fe++,Mn)6(Fe+++,Al)3Si6O20(OH)5
Composition:(Molecular Weight = 1,052.69 gm)Manganese 10.44 %
MnAluminum 1.92 %
AlIron 33.16 %
FeSilicon 16.01 %
SiHydrogen 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
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