Sulvanite
Sulvanite is a very rare copper vanadium sulfide mineral rarely found as well formed crystals but most often as massive metallic aggregates. Its attractive bronze yellow color combined with interlaced green Vésigniéite veins makes for very attractive gems.
Distribution: From the Edelweiss mine, Burra district, South Australia (Type Locality). At Tsumeb, Namibia. From Kipushi, Katanga Province, Congo (Shaba Province, Zaire). At the Oyu Tolgoi porphyry Cu–Au deposit, Gobi Desert, Mongolia. In the USA, in the Thorpe Hills, and near Mercur, Tooele County, Utah; in the Redhouse Barite mine, near Golconda, Humboldt County, Nevada. On the Rough claims, north of Sifton Pass, British Columbia, Canada. At Pay-Khoy, in the middle stream of the Silova-Yakha River, Russia. From the Ceragiola quarry, near Carrara, Tuscany, Italy. At Bor, Serbia. In the Assarel and Medet deposits, Bulgaria. From Ponte Castiola, Corsica, France. On Koksín Hill, near Mítov, Czech Republic.
| Chemical Formula: | Cu3VS4 |
| Copper Vanadium Sulfide | |
| Molecular Weight: | 369.84 gm |
| Composition: | Vanadium | 13.77 % | V | ||
| Copper | 51.55 % | Cu | |||
| Sulfur | 34.68 % | S | |||
| 100.00 % |
| Crystallography: | Isometric – Hextetrahedral |
| Crystal Habit: | Crystals cubic, to 2.5 cm, but most commonly massive. |
| Twinning: | None |
| Cleavage: | Perfect on {001} |
| Fracture: | Irregular/Uneven |
| Tenacity: | Brittle |
| Moh’s Hardness: | 3.5; VHN = 135–157 (100 gload) |
| Density: | 3.86 – 4.00 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Bronze-gold; pale yellow in polished section |
| Transparency: | Opaque |
| Luster: | Metallic, tarnishes to dull |
| Refractive Index: | R: (400) 28.1, (420) 26.4, (440) 24.4, (460) 24.1, (480) 27.6, (500) 31.4, (520) 30.6, (540) 28.4, (560) 27.7, (580) 29.4, (600) 30.0, (620) 30.8, (640) 29.5, (660) 27.9, (680) 26.7, (700) 25.9 |
| Birefringence: | None; Opaque |
| Dispersion: | n/a |
| Pleochroism: | None |
| Anisotrophism: | Weak, rarely; yellow-white |
