Libethenite
Libethenite is a rare copper phosphate hydroxide mineral. It forms striking, dark green orthorhombic crystals. It was discovered in 1823 in Ľubietová, Slovakia and is named after the German name of that locality (Libethen). Libethenite has also been found in the Miguel Vacas Mine, Conceição, Vila Viçosa, Évora District, Portugal, and in Tier des Carrières, Cahai, Vielsaim, Stavelot Massif, Luxembourg Province, Belgium.
| Libethenite | |
|---|---|
| General | |
| Category | Phosphate minerals |
| Formula (repeating unit) | Cu2PO4OH |
| IMA symbol | Lib |
| Strunz classification | 8.BB.30 |
| Crystal system | Orthorhombic |
| Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
| Space group | Pnnm |
| Identification | |
| Color | Light to dark green, blackish green, olive-green |
| Crystal habit | Globular, druzy, slender prismatic |
| Cleavage | Indistinct on [100] and [010] |
| Fracture | Irregular, uneven to conchoidal |
| Tenacity | Brittle |
| Mohs scale hardness | 4 |
| Luster | Vitreous, greasy |
| Streak | light green |
| Specific gravity | 3.6 – 4, Average = 3.8 |
| Optical properties | Biaxial (−) |
| Refractive index | nα = 1.701 – 1.704 nβ = 1.743 – 1.747 nγ = 1.787 – 1.790 |
| References | |
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.