Dioptase

Dioptase is an intense emerald-green to bluish-green copper cyclosilicate mineral. It is transparent to translucent. Its luster is vitreous to sub-adamantine. Its formula is CuSiO3·H2O (also reported as CuSiO2(OH)2). It has a hardness of 5, the same as tooth enamel. Its specific gravity is 3.28–3.35, and it has two perfect and one very good cleavage directions. Additionally, dioptase is very fragile and specimens must be handled with great care. It is a trigonal mineral, forming 6-sided crystals that are terminated by rhombohedra.Dioptase from the Tsumeb Mine, Tsumeb, NamibiaDioptase with Cerussite, Christoff Mine, Kunene Region, Namibia. 6.9 × 5.7 × 4.8 cmDioptase on Chrysocolla, Otjikotu, Kunene Region, Namibia. 6.8 × 5.5 × 4.5 cmDioptase crystal, Kimbedi, Pool Department, Republic of Congo (Brazzaville). Size: 2.0 × 1.7 × 1.4 cmPristine Dioptase crystals, Tsumeb Mine, Tsumeb, Namibia. 4 × 4 × 1 cmDioptase on Shattuckite, Kaokoveld Plateau, Kunene Region, Namibia. Size: 2.5 × 2.1 × 2.0 cm Dioptase is an intense emerald-green to bluish-green copper cyclosilicate mineral. It is transparent to translucent. Its luster is vitreous to sub-adamantine. Its formula is CuSiO3·H2O (also reported as CuSiO2(OH)2). It has a hardness of 5, the same as tooth enamel. Its specific gravity is 3.28–3.35, and it has two perfect and one very good cleavage directions. Additionally, dioptase is very fragile and specimens must be handled with great care. It is a trigonal mineral, forming 6-sided crystals that are terminated by rhombohedra.