Cobaltoan Calcite
Calcite (Variety: Cobaltoan Calcite) · Mineral Specimen / Semi-Precious Gemstone
Crystal System
Trigonal; typically occurs as rhombohedral crystals, scalenohedral, or more commonly in massive, drusy, or botryoidal forms.
Mineral Group
Carbonates (Calcite group)
Chemical Formula
(Ca,Co)CO3 (Calcium Carbonate with Cobalt inclusions influencing the magenta color)
Formation Process
Hydrothermal formation within the oxidation zones of cobalt-bearing ore deposits, where cobalt replaces some calcium in the lattice.
About This Crystal
Exhibits a distinct vibrant magenta to rose-pink color. The specimen shown features a drusy surface of tiny, sparkling crystalline faces (vitreous luster) atop a matrix of paler pink calcite and darker host rock.
Physical Characteristics
Pink to magenta body color; white streak; perfect rhombohedral cleavage (though not visible in drusy habit); specific gravity of 2.71; brittle tenacity; often fluoresces pink under UV light.
Optical Properties
Uniaxial negative; extreme birefringence; refractive index of 1.486–1.658; vitreous to pearly luster on cleavage surfaces.
Hardness & Durability
Origin Region
Notably sourced from the Bou Azzer district in Morocco, Katanga in the Democratic Republic of Congo, and Tsumeb in Namibia. Typical of hydrothermal basins.
Hardness & Durability
Mohs hardness of 3; very soft and brittle. Not suitable for most jewelry unless protected. Sensitive to acids (effervesces in HCl).
Care & Maintenance
Clean only with warm, soapy water; avoid ultrasonic or steam cleaners. Must be kept away from household acids (vinegar/citrus). Store separately to prevent scratching.
Rarity & Value
Uncommon as a variety; value is determined by the intensity of the pink-magenta saturation and the quality of crystal formations. Moroccan specimens are highly prized by collectors.
Special Characteristics
Characterized by its distinct cobalt-induced coloration and bright drusy sparkle. Strong pink fluorescence is a key identifying feature for many specimens.
Lore & History
Historically recognized as a secondary mineral in cobalt mines. In metaphysical traditions, it is known as the "Stone of Unconditional Love" and associated with the Heart Chakra, believed to aid in emotional healing.