Spherocobaltite
Cobaltocalcite, also known as Spherocobaltite, is a dimorph of Calcite. It is a rare and beautiful mineral and very rare gem. It comes under the category of Carbonate mineral and with the chemical composition of CoCO3(cobalt carbonate). The crystal habit of Spherocobaltite is Crystals uncommon, rhombohedral, flat discoidal, modified, to 5 mm; commonly compact radiated, concentric, spherical, massive, and in crusts and its crystal system is Trigonal. The Hardness which comes between 3.0 to 4.0, when comes to the cleavage of this stone is Perfect on [1011] (rhombohedral). Mostly Pink, Rose red, Gray-brown, Black in color. The Optical properties are Uniaxial (–) with 1.885 – 1.600 Refractive Index. The Birefringence value of the stone is 0.285 and also its Specific gravity is 4.10 – 4.13 (g/cm3). It is usually found in shades of pink from pale pink to rose red, to deep pinkish red. Current sources are Morocco, Spain, and Congo (Zaire).
| Category: | Carbonate mineral |
| Formula: | CoCO3 |
| cobalt carbonate | |
| Crystallography: | Trigonal-Hexagonal – Scalenohedral |
| Crystal Habit: | Crystals uncommon, rhombohedral, flat discoidal, modified, to 5 mm; commonly compact radiated, concentric, spherical, massive, and in crusts. |
| Twinning: | Observed |
| Cleavage: | [1011] Perfect, [1011] Perfect, [1011] Perfect (perfect rhombohedral) |
| Fracture: | Subconchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 3.0 – 4.0 |
| Density: | 4.10 – 4.13 (g/cm3) |
| Radioactivity: | Not Radioactive |
| Color: | Pink, Rose red, Gray brown, Black |
| Transparency: | Transparent to Translucent |
| Luster: | Vitreous to Adamantine |
| Refractive Index: | 1.885 – 1.600 Uniaxial ( – ) |
| Birefringence: | 0.2850 (very high) |
| Dispersion: | Strong |
| Pleochroism: | Dichroic: O = violet-red; E = rose-red |
