General Information:
 Chemical Formula:
Mn++9Zn6Sb+++++2Si4O28
 Composition:
(Molecular Weight = 1,690.61 gm)
Manganese 29.25 % Mn
Zinc 23.21 % Zn
Silicon 6.65 % Si
Antimony 14.40 % Sb
Oxygen 26.50 % O 
 Empirical Formula:
Mn2+9Zn6Sb2Si4O28
 Environment:
Metamorphosed, weathered Zn-Mn deposit.
 Locality:
Franklin and Sterling Hill, Sussex County, New Jersey, USA.
 Name Origin:
Named for Pope Yeatman (1861-1953), U. S. Mining engineer.
Physical Properties:
 Cleavage:
[100] Good
 Color:
clove brown.
 Density:
4.91 - 5.02, Average = 4.96
 Habits:
Platy - Sheet forms (e.g. micas)., Anhedral Grains - Granular minerals without the expression of crystal shapes,
 Hardness:
4 - Fluorite
 Luster:
Vitreous (Glassy)
 Streak:
pale brown
More details...

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