Hemimorphite

Hemimorphite, is a sorosilicate mineral which has been mined from days of old from the upper parts of zinc and lead ores, chiefly associated with smithsonite. It was often assumed to be the same mineral and both were classed under the same name of calamine. In the second half of the 18th century it was discovered that there were two different minerals under the heading of calamine - a zinc carbonate and a zinc silicate, which often closely resembled each other.
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Noun
1. a white mineral; a common ore of zinc
(synonym) calamine
(hypernym) mineral
(substance-holonym) calamine lotion
(substance-meronym) cadmium, Cd, atomic number 48

n. hemimorphite, a white mineral; a common ore of zinc

General Information:
 Chemical Formula:
Zn4Si2O7(OH)2·(H2O)
 Composition:
(Molecular Weight = 481.76 gm)
Zinc 54.29 % Zn
Silicon 11.66 % Si
Hydrogen 0.84 % H 
Oxygen 33.21 % O 
 Empirical Formula:
Zn4Si2O7(OH)2·(H2O)
 Environment:
Veins and beds in stratified calcareous rocks.
 Locality:
Nerchinak in Transbaikalia, Siberia.
 Name Origin:
Named after the hemimorphic nature of the crystals.
Physical Properties:
 Cleavage:
[110] Perfect
 Color:
brown, colorless, greenish gray, yellow brown, or white.
 Density:
3.4 - 3.5, Average = 3.45
 Diaphaniety:
Transparent to translucent
 Habits:
Massive - Uniformly indistinguishable crystals forming large masses., Stalactitic - Shaped like pendant columns as stalactites or stalagmites (e.g. calcite)., Mammillary - Larger "bre ast-like" rounded forms resembling botry
 Hardness:
5 - Apatite
 Luminescence:
None.
 Luster:
Vitreous (Glassy)
 Streak:
white
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