Vesignieite

General Information:
 Chemical Formula:
Cu3Ba(VO4)2(OH)2
 Composition:
(Molecular Weight = 591.86 gm)
Barium 23.20 % Ba
Vanadium 17.21 % V 
Copper 32.21 % Cu
Hydrogen 0.34 % H 
Oxygen 27.03 % O 
 Empirical Formula:
BaCu3(VO4)2(OH)2
 Name Origin:
Named after the French mineral collector, L. Vesignie (1870-1954).
Physical Properties:
 Cleavage:
[001] Good
 Color:
yellow green, dark green, or olive green.
 Density:
4 - 4.1, Average = 4.05
 Habits:
Lamellar - Thin laminae producing a lamellar structure., Euhedral Crystals - Occurs as well-formed crystals showing good external form., Platy - Sheet forms (e.g. micas).
 Hardness:
3.5-4 - Copper Penny-Flourite
 Luster:
Vitreous (Glassy)
 Streak:
light green
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