Apachite - Encyclopedia
Class : Silicates
Subclass : Cyclosilicates
Crystal System : Monoclinic
Chemistry : Cu9Si10O29 11H2O
Rarity : Very rare
Apachite is an extremely rare hydrated copper silicate which forms small fibroradiated spherolites composed of tiny crystals of a magnificent sky blue. It owes its name to the Apache Indians, inhabitants of the discovery region : the Christmas Mine (Arizona). It is a metamorphic mineral found in tactites (calcium hornfels) replacing an assembly of garnet, diopside, calcite and sulphides.
Main photo : Apachite and calcite from the Christmas Mine, Arizona, USA - © Stephan Wolfsried
Apachite in the World
Right photo : Apachite from the Christmas Mine, Arizona, USA - © Stephan Wolfsried
Twinning
No known twins for this mineral species.
Fakes and treatments
No fake identified for this mineral species, but sometimes confused with fibrous dioptase.
Hardness : 2
Density : 2.80
Fracture : Conchoidal to irregular
Trace : Pale blue
TP : Translucent to transparent
RI : 1.610 to 1.650
Birefringence : 0.040
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None
Solubility : -
Magnetism : None
Radioactivity : None