Spertiniite | |
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General | |
Category | Oxide mineral |
Formula (repeating unit) | Cu(OH)2 |
IMA symbol | Sni[1] |
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 | [2][3][4] |
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.[3]