Berzelianite
Berzelianite is just a copper selenide mineral that is relatively soft, with a Moh’s hardness of just 2.7, and it is somewhat malleable. It has a lustre that is metallic silver-white to shiny lead-grey colour when freshly broken and easily tarnishes to iridescent blue-grey. Berzelianite was named for Jöns Jacob Berzelius (1779–1848), Swedish chemist, who discovered selenium, one of the primary components of Berzelianite. A report that is recent the existence of the complete solid-solution series between high Digenite [cubic, high-temperature Digenite] and Berzelianite (Pirard & Hatert, 2008).
Distribution: At Skrikerum, near Tryserum, Kalmar, Sweden (Type Locality). From Lerbach, Tilkerode, Zorge, Clausthal, and St. Andreasberg, Harz Mountains; at Niederschlema, Saxony; and the Mullenbach uranium deposit, Black Forest, Germany. In the Czech Republic, in the Habrí and Bukov mines, near Tisnova; during the Petrovice uranium deposit, near Ždar; and the Predborice uranium deposit, near Krásna Hora. Through the Kyzylalmasay gold deposit, Uzbekistan. In the Sierra de Umango, and at Tuminico, Sierra de Cacho, Los Angeles Rioja Province, Argentina. From the Elefante prospect, near the Serra Pelada Au–Pd–Pt deposit, Pará, Brazil. At Rejang-Lebong, Sumatra. From Kalgoorlie and in the Copper Hills prospect, East Pilbara area, Western Australia, and also at El Sharana, Northern Territory, Australia. In the Pinky Fault uranium deposit, Lake Athabasca, Saskatchewan, Canada. From the vein that is Durant Aurora region, Mineral County, Nevada, USA.
| Category: | Selenide minerals |
| Chemical Formula: | Cu2Se |
| Copper Selenide | |
| Molecular Weight: | 206.05 gm |
| Composition: | Copper | 61.68 % | Cu | ||
| Selenium | 38.32 % | O | |||
| 100.00 % |
| Crystallography: | Isometric – Hexoctahedral |
| Crystal Habit: | As thin dendritic crusts; fine-grained and disseminated as powdery inclusions. |
| Twinning: | None |
| Cleavage: | None |
| Fracture: | Irregular/Uneven |
| Tenacity: | Malleable |
| Moh’s Hardness: | 2.7; VHN = 21–24 (100 g load) |
| Density: | 6.71 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Silver-White, shiny lead-grey; easily tarnishes iridescent blue-grey |
| Transparency: | Opaque |
| Luster: | Metallic |
| Birefringence: | 0.000 (Isotropic) |
| Dispersion: | n/a |
| Pleochroism: | None |
| Anisotrophism: | Isotropic; may be slightly anisotropic |
