General Information:
Chemical Formula:
Cu5(AsO4)2(OH)4
Composition:
(Molecular Weight = 681.61 gm)
Copper 46.61 % Cu
Arsenic 21.98 % As
Hydrogen 0.89 % H
Oxygen 30.51 % O
Empirical Formula:
Cu5(AsO4)2(OH)4·(H2O)
Environment:
Dimorphous with cornubite.
Name Origin:
Named after the English leader Cornwall.
Physical Properties:
Cleavage:
None
Color:
light green, dark green, or black green.
Density:
4 - 4.16, Average = 4.08
Diaphaniety:
Subtranslucent
Habits:
Massive - Uniformly indistinguishable crystals forming large masses., Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite), Encrustations - Forms cr ust-like aggregates on matrix.
Hardness:
4-5 - Fluorite-Apatite
Luster:
Earthy (Dull)
Streak:
apple green
More details...