General Information:
Chemical Formula:
6Fe0.9S·5(Mg,Fe++)(OH)2
Composition:
(Molecular Weight = 904.38 gm)
Magnesium 12.77 % Mg
Iron 51.56 % Fe
Hydrogen 0.22 % H
Sulfur 31.91 % S
Oxygen 3.54 % O
Empirical Formula:
9(Fe2+0.9)S95(Mg0.95)5(Fe2+0.05)(OH)2
Environment:
Ultramafic bodies, diamond pipes, and carbonaceous chondrite meteorites.
IMA Status:
Approved IMA 1971
Locality:
Mamonovo deposit, Voronezh.
Name Origin:
Named for Mitrofan S.Tochilin (1910-1968), Russian scientist.
Physical Properties:
Cleavage:
[001] Distinct
Color:
bronze black.
Density:
2.96 - 2.99, Average = 2.97
Diaphaniety:
Opaque
Habits:
Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite), Cylindrical - Shaped like a cylinder., Acicular - Occurs as needle-like crystals.
Hardness:
1-1.5 - Talc or a little harder
Luster:
Metallic
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