Dioptase

Dioptase is emerald-green to bluish-green copper cyclosilicate mineral. Its luster is vitreous to sub-adamantine with the chemical formula is CuSiO3·H2O. It has a hardness of 5 on the Moh scale with a specific gravity of 3.28–3.35 and it has two perfect and one very good cleavage directions. Dioptase is very fragile and must be handled with great care. It is a trigonal mineral, forming 6-sided crystals that are terminated by rhombohedra.

Our specimens are primarily from Congo, but we occasionally get some pieces from the long closed Tsumeb mine which are highly sought after by collectors.