Dioptase is copper’s answer to emerald: intense bluish-green micro-crystals with extraordinary saturation. Fragile (Mohs 5, perfect cleavage), it is a collector’s treasure rather than a ring stone — Kazakhstan, Namibia’s Tsumeb and the Congo produced the finest specimens.GEMIC Institute offers natural dioptase certified by our laboratory, each photographed exactly as sold. Unique specimens; worldwide tracked delivery with our 30-day inspection period.