| Spherocobaltite | |
| Category: | Carbonate mineral |
| Formula: | CoCO3 |
| Imasymbol: | Scbt[1] |
| Molweight: | 118.94 g/mol |
| Strunz: | 5.AB.05 |
| System: | Trigonal |
| Class: | Hexagonal scalenohedral (m) H-M symbol: (2/m) |
| Symmetry: | Rc |
| Unit Cell: | a = 4.65, c = 14.95 [Å]; Z = 6 |
| Color: | Most commonly dark magenta red; pink to red, brown, brownish red, grey, greyish red, velvet-black (due to surface alteration) |
| Habit: | Encrustations - forms crust-like aggregates on matrix, crystals uncommon: rhombohedral to discoidal |
| Cleavage: | Perfect rhomboidal cleavage |
| Mohs: | 4 |
| Luster: | Vitreous |
| Refractive: | nε = 1.600, nω = 1.885 |
| Opticalprop: | Uniaxial (–) |
| Birefringence: | 0.285 |
| Pleochroism: | Dichroic: O = violet-red; E = rose-red |
| Streak: | Pink |
| Gravity: | 4.13 |
| Diaphaneity: | Transparent to translucent |
| References: | [2] [3] [4] |
Spherocobaltite or sphaerocobaltite is a cobalt carbonate mineral with chemical composition CoCO3. In its (rare) pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. It crystallizes in the trigonal crystal system.
Spherocobaltite was first described in 1877 for an occurrence within cobalt and nickel veins in the St. Daniel Mine of the Schneeberg District, Ore Mountains, Saxony, Germany. The name is from the Greek "sphaira", sphere, and cobalt, in reference to its typical crystal habit and composition.[2] It occurs within hydrothermal cobalt-bearing mineral deposits as a rare phase associated with roselite, erythrite, annabergite and cobalt rich calcite and dolomite.[4]