mineral

Cobaltian Calcite

Cobalt-bearing Calcite (Ca,Co)CO3

Hardness: 3 on Mohs scale; Color: Pink to magenta/rose; Luster: Vitreous to pearly; Crystal structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral; Specific gravity: 2.7 to 2.9

Hardness: 3 on Mohs scale
Color: Pink to magenta/rose
Luster: Vitreous to pearly

Identified April 5, 2026More mineral →

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Physical properties

Hardness: 3 on Mohs scale; Color: Pink to magenta/rose; Luster: Vitreous to pearly; Crystal structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral; Specific gravity: 2.7 to 2.9

Formation & geological history

Formed through hydrothermal processes in the oxidation zones of cobalt-rich mineral deposits. It is a secondary mineral often appearing when cobalt replaces calcium in the calcite lattice.

Uses & applications

Primarily used as a collector specimen and in metaphysical practices. Occasionally used for small ornamental carvings or cabochons, though its softness limits jewelry applications.

Geological facts

The intense pink color is caused by the presence of cobalt. While it looks like rhodochrosite, it is actually a variety of calcite. It is often referred to as 'Sphaerocobaltite' in some trade circles, though true sphaerocobaltite is a distinct mineral species (CoCO3).

Field identification & locations

Identify in the field by its distinct magenta color and rhombohedral cleavage. It will react and effervesce strongly with cold dilute hydrochloric acid. Most high-quality specimens come from the Katanga Province in the Democratic Republic of the Congo.