General Information:
Chemical Formula:
Mn9Mg4Zn2As2Si2O17(OH)14
Composition:
(Molecular Weight = 1,288.71 gm)
Magnesium 7.54 % Mg
Manganese 38.37 % Mn
Zinc 10.15 % Zn
Silicon 4.36 % Si
Hydrogen 1.09 % H
Oxygen 38.49 % O
Empirical Formula:
Mn2+9Mg4Zn2Si2O17(OH)14
Environment:
Metamorphosed zinc-manganese deposit.
Locality:
Sterling Hill, Franklin, Sussex Co., New Jersey, USA.
Name Origin:
Named for J. J. McGovern (1915-), Franklin miner and mineral collector.
Physical Properties:
Cleavage:
[001] Perfect
Color:
bronze brown, light brown, dark reddish brown, or reddish brown.
Density:
3.72
Diaphaniety:
Translucent
Habits:
Massive - Granular - Common texture observed in granite and other igneous rock., Micaceous - Platy texture with "flexible" plates.,
Luminescence:
Non-fluorescent.
Luster:
Vitreous - Pearly
Streak:
brown
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