Spertiniite
| Spertiniite | |
|---|---|
Spertiniite from Dzhezkazgan, Kazakhstan (size: 5 mm) | |
| General | |
| Category | Oxide mineral |
| Formula | Cu(OH)2 |
| IMA symbol | Sni |
| Strunz classification | 4.FD.05 |
| Dana classification | 6.2.4.1 |
| Crystal system | Orthorhombic |
| Crystal class | Pyramidal (mm2) H-M symbol: (mm2) |
| Space group | Cmc21 |
| Unit cell | a = 2.95 Å, b = 10.59 Å c = 5.27 Å; Z = 4 |
| Identification | |
| Formula mass | 97.56 g/mol |
| Color | Blue, blue-green |
| Crystal habit | Flat tabular crystals occurring in radial to botryoidal aggregates |
| Cleavage | None |
| Tenacity | Brittle |
| Mohs scale hardness | Soft |
| Luster | Vitreous |
| Diaphaneity | Transparent |
| Specific gravity | 3.93 |
| Optical properties | Biaxial |
| Refractive index | nα = 1.720, nβ= n.d., nγ = > 1.800 |
| Pleochroism | Strong; X = colorless; Z = dark blue |
| Other characteristics | Decomposes in hot water (synthetic) |
| References | |
Spertiniite is a rare copper hydroxide mineral. Chemically, it is copper(II) hydroxide with the formula Cu(OH)2. It occurs as blue to blue-green tabular orthorhombic crystal aggregates in a secondary alkaline environment altering chalcocite. Associated minerals include chalcocite, atacamite, native copper, diopside, grossular, and vesuvianite.