Chrysocolla

Chrysocolla is a gemstone with a beautiful sky blue to bluish-green color. Copper in its chemical structure is responsible for the bright attractive color. It is often multicolored with inclusions or veining of black and brown matrix material. Chrysocolla"s lack of widespread gem use is due to its low hardness and lack of durability. It is sometimes coated or admixed with harder Quartz, and these harder, more solid forms are better fit for gemstone use. 

Chemical Formula	Cu2H2Si2O5(OH)4
Color	Blue, Green, Multicolored
Hardness	2Â -Â 4
Crystal System	Orthorhombic
Refractive Index	1.4Â -Â 1.6
SG	2.0Â -Â 2.2
Transparency	Opaque
Double Refraction	None
Luster	Vitreous to greasy
Cleavage	None
Mineral Class	Chrysocolla