Cobaltite
Cobaltite is a rare mineral that is sulfide is opaque and metallic. It is occasionally available as cabochons from massive material and rarely faceted. A gem that is faceted be an uncommon curiosity for collectors. Cabochons and faceted gems are attractive due to the reddish that is a beautiful silvery metallic appearance of the mineral. Some pseudo pyritohedral that is natural can happen to possess been roughly faceted by our mother earth.
Cobaltite deposits often have a weathering crust of minerals such as Erythrite. Since cobalt is a strong color metal, minerals like Erythrite are strongly colored, in this case deep pink to purple that is bright. Miners called these minerals that are colorful cobalt blooms” and utilized them as indicators associated with the existence of cobalt ores such as for example Cobaltite.
Fine, well-shaped crystals are available from Columbus Mine, Cobalt, Coleman Township, Timiskaming District, Ontario, Canada; Tunaberg, Nyköping, Södermanland, Sweden; Håkansboda, Lindesberg, Västmanland, Sweden; and Riddarhyttan, Skinnskatteberg, Västmanland, Sweden.
| Category: | Sulfide mineral |
| Chemical Formula: | CoAsS |
| Cobalt Arsenic Sulfide | |
| Molecular Weight: | 165.92 gm |
| Composition: | Cobalt | 35.52 % | Co | ||
| Arsenic | 45.16 % | As | |||
| Sulfur | 19.33 % | S | |||
| 100.00 % |
| Crystallography: | Orthorhombic – Pyramidal |
| Crystal Habit: | Commonly as pseudocubic or pseudo pyritohedral crystals, or combinations having striated faces as with pyrite, to as large as 8 cm, also as pseudo-octahedra; granular massive. |
| Twinning: | About {111} as a pseudocubic three-fold axis, with {011} and {111} of the pseudocubic habit as twin planes, rare. Twin lamellae are commonly observed in polished section, which may exhibit a flamelike texture. |
| Cleavage: | Perfect on {001} |
| Fracture: | Irregular/Uneven |
| Tenacity: | Brittle |
| Moh’s Hardness: | 5.5 |
| Density: | 6.33 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Health Warning: | CAUTION: Contains Arsenic, a poisonous element – always wash hands after handling. Avoid inhaling dust when handling or breaking. Never lick or ingest. |
| Color: | Silvery White to Reddish Silvery White, Violet Steel Gray, or Black |
| Transparency: | Opaque |
| Luster: | Metallic |
| Refractive Index: | R: (400) 48.2, (420) 48.0, (440) 47.7, (460) 47.8, (480) 48.2, (500) 48.9, (520) 49.6, (540) 50.4, (560) 51.2, (580) 51.9, (600) 52.6, (620) 53.1, (640) 53.5, (660) 53.7, (680) 53.8, (700) 53.8 |
| Birefringence: | None; Opaque |
| Dispersion: | None; Opaque |
| Pleochroism: | Very weak; on grain boundaries |
