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.
General | |
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Category | Cyclosilicates |
Formula (repeating unit) |
Cu6Si6O18·6H2O |
IMA symbol | Dpt |
Strunz classification | 9.CJ.30 |
Crystal system | Trigonal |
Crystal class | Rhombohedral (3) H-M Symbol: (3) |
Space group | R3 (No. 148) |
Unit cell | a = 14.566, c = 7.778 [Å]; Z = 18 |
Identification | |
Color | Dark teal, emerald green |
Crystal habit | Six sided prisms terminated by rhombohedrons to massive |
Cleavage | Perfect in three directions |
Fracture | Conchoidal |
Tenacity | Brittle |
Mohs scale hardness | 5 |
Luster | Vitreous |
Streak | Green |
Diaphaneity | Transparent to translucent |
Specific gravity | 3.28–3.35 |
Optical properties | Uniaxial (+) |
Refractive index | nω = 1.652 - 1.658 nε = 1.704 - 1.710 |
Birefringence | δ = 0.052 |