General Information:
Chemical Formula:
Cu4(SO4)(OH)6·(H2O)
Composition:
(Molecular Weight = 470.31 gm)
Copper 54.05 % Cu
Hydrogen 1.71 % H
Sulfur 6.82 % S
Oxygen 37.42 % O
Empirical Formula:
Cu4(SO4)(OH)6·(H2O)
IMA Status:
Approved IMA 1967
Name Origin:
Named after the geochemist, E. W. Posnjak (1888-1949).
Physical Properties:
Cleavage:
[???] Perfect
Color:
blue or dark blue.
Density:
3.4
Habits:
Crystalline - Fine - Occurs as well-formed fine sized crystals., Encrustations - Forms crust-like aggregates on matrix., Platy - Sheet forms (e.g. micas).
Hardness:
2.5-3 - Finger Nail-Calcite
Luster:
Vitreous (Glassy)
Streak:
greenish blue
More details...