Dioptase is a rare copper mineral. It is too rare to be used as an ore for copper, and too brittle as a jewelry raw material. But it is very much appreciated by collectors for its rich color and medium-sized, but well-formed crystals.
You can see dioptase stone for sale and buy it in the Minerals of Russia online store.
|Crystal class||Rhombohedral (3)
H-M Symbol: (3)
|Space group||R3 (No. 148)|
|Unit cell||a = 14.566, c = 7.778 [Å]; Z = 18|
|Color||Dark teal, emerald green|
|Crystal habit||Six sided prisms terminated by rhombohedrons to massive|
|Cleavage||Perfect in three directions|
|Mohs scale hardness||5|
|Diaphaneity||Transparent to translucent|
|Optical properties||Uniaxial (+)|
|Refractive index||nω = 1.652 - 1.658 nε = 1.704 - 1.710|
|Birefringence||δ = 0.052|