Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
Cabochons are interesting because of the lovely reddish metallic appearance of this mineral. Cut stones are infrequently seen and are cut only as a curiosity by the collector who wants to have one of everything.
| Data | Value |
|---|---|
| Name | Cobaltite |
| Colors | Silvery white to reddish, steel gray with a violet tinge; blackish gray. |
| Crystallography | Orthorhombic. Crystals usually cubes and pyritohedra or combinations of forms; also massive; granular. |
| Luster | Metallic. |
| Hardness | 5.5 |
| Fracture | Uneven |
| Specific Gravity | 6.3 |
| Cleavage | Perfect 1 direction |
| Stone Sizes | Massive material would cut stones of any desired size. |
| Luminescence | None. |
| Luminescence Present | No |
| Transparency | Opaque. |
| Absorption Spectrum | Not diagnostic. |
| Formula |
CoAsS. |
| Pleochroism |
None. |
Streak: Grayish black.
Occurrence: High temperature deposits, in metamorphosed rocks, and in vein deposits. Colorado; Idaho; California.
Dashkesan, Ajerbaijan, USSR; India: Sonora, Mexico; Tunaberg, Sweden; Norway; Cerrnany; Cornwall. England; Western Australia. Cobalt, Ontario: in masses and fine crystals.
Comments: Cabochons are interesting because of the lovely reddish metallic appearance of this mineral. Cut stones are infrequently seen and are cut only as a curiosity by the collector who wants to have one of everything.
Name: From the composition.
IGS Newsletter