Hübnerite
Hübnerite is really a member that is uncommon of Wolframite mineral series which also includes Ferberite. Hübnerite could be the manganese end that is rich while Ferberite could be the Iron rich end member and Wolframite is the intermediate between the two. Hübnerite is a small ore of Tungsten which will be a significant element that is industrial. Hübnerite is a real collector that is an unusual gem. Gemstones are usually really dark reddish brown to black. It is an extremely mineral that is interesting that it has high refractive index and birefringence, strong dispersion, distinct pleochroism, acutely high density, adamantine to a metallic luster and it is distinctly anisotropic.
Hübnerite is bought at many places in the USA such as for example Arizona, Ca, Colorado, Idaho, Nevada, New Mexico and Southern Dakota. Other locations being worldwide Australia, France, Czech Republic and Peru.
| Category: | Oxide minerals |
| Formula: | MnWO4 |
| Tungsten(IV) Permanganate | |
| Crystallography: | Monoclinic – Prismatic |
| Crystal Habit: | Crystals are prismatic; also lamellar, massive and granular. |
| Twinning: | Common as simple contact, as interpenetrant twins, lamellar |
| Cleavage: | [010] Perfect |
| Fracture: | Irregular to Uneven |
| Tenacity: | Brittle |
| Moh’s Hardness: | 4.0 – 4.5 |
| Density: | 7.12 – 7.20 (g/cm3) (very heavy) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Brown, Reddish Brown, Brownish Black, rarely Red |
| Transparency: | Transparent, Translucent, Opaque |
| Luster: | Adamantine, Resinous, Metallic |
| Refractive Index: | 2.17 – 2.32 Biaxial ( + ) |
| Birefringence: | 0.1200 – 0.1300 |
| Dispersion: | Relatively strong |
| Pleochroism: | X = yellow to green, orange-red; Y = yellowish brown to greenish yellow, red-orange to red; Z = green, brick red to red |
| Anisotrophism: | Strong; Color in reflected light: light gray; Internal reflections: white to brownish |
| Other: |
Distinctly Anisotropic; internal reflections: deep blood red |
