Chalcomenite - Encyclopedia
Class : Oxides and hydroxides
Subclass : Selenites
Crystal system : Orthorhombic
Chemistry : CuSeO3 2H2O
Rarity : Rare
Chalcomenite belongs to the little-represented subclass of selenites. It is a secondary mineral which crystallizes in the oxidation zone of copper and selenium deposits by oxidation of selenides. Its name comes from the Greek khalcos (copper) and mene (contraction of selene, the moon). It forms tiny acicular crystals of a beautiful blue color, with frequently rounded faces.
Main photo : Chalcomenite from Baccu Locci, Sardinia, Italy © Italo Campostrini
Chalcomenite in the World
Twinning and special crystallizations
No twin known for this mineral species.
Fakes and treatments
No fakes identified for this mineral species.
Hardness : 2 to 2.5
Density : 3.35
Fracture : Conchoidal
Streak : Blue
TP : Translucent to transparent
RI : 1.712 to 1.732
Birefringence : 0.020
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None
Solubility : Acids
Magnetism : None
Radioactivity : None