General Information:
Chemical Formula:
K2Fe++5Fe+++3Al(SO4)12·18H2O
Composition:
(Molecular Weight = 2,028.99 gm)
Potassium 3.85 % K
Aluminum 1.33 % Al
Iron 22.02 % Fe
Hydrogen 1.79 % H
Sulfur 18.96 % S
Oxygen 52.04 % O
Empirical Formula:
K2Fe2+5Fe3+3Al(SO4)12·18(H2O)
Name Origin:
Named after the Italian physicist, A. G. A. A. Volta (1745-1841).
Physical Properties:
Cleavage:
None
Color:
greenish black, dark green, olive green, or black.
Density:
2.6 - 2.8, Average = 2.7
Diaphaniety:
Opaque
Habits:
Massive - Granular - Common texture observed in granite and other igneous rock., Crystalline - Fine - Occurs as well-formed fine sized crystals.,
Hardness:
3-3.5 - Calcite-Copper Penny
Luminescence:
None.
Luster:
Silky
Streak:
grayish green
More details...