General Information:
Chemical Formula:
Pb3Cu(CrO4)(SiO3)(OH)4·2(H2O)
Composition:
(Molecular Weight = 981.28 gm)
Chromium 5.30 % Cr
Copper 6.48 % Cu
Silicon 2.86 % Si
Hydrogen 0.82 % H
Lead 63.35 % Pb
Oxygen 21.20 % O
Empirical Formula:
Pb3Cu(CrO4)(SiO3)(OH)4·2(H2O)
Environment:
Encrusting dioptase.
IMA Status:
Approved IMA 1979
Locality:
Mammoth mine, Tiger, Pinal County, Arizona, USA.
Name Origin:
Named for Louis Charles Henri Macquart (1745-1803), French chemist who brought to France from Russia the samples of crocoite in which the element chromium was discovered.
Physical Properties:
Cleavage:
[100] Good
Color:
orange.
Density:
5.49
Habits:
Euhedral Crystals - Occurs as well-formed crystals showing good external form., ,
Hardness:
3.5 - Copper Penny
Luster:
Adamantine
Streak:
light orange
More details...