mineral

Blue Calcite

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: Powdery light blue to sky blue; Luster: Vitreous to waxy/pearly; Crystal structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral in three directions; Specific gravity: 2.71

Hardness: 3 on Mohs scale
Color: Powdery light blue to sky blue
Luster: Vitreous to waxy/pearly

Identified June 13, 2026More mineral →

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Physical properties

Formation & geological history

Formed through sedimentary processes, often by precipitation from marine waters or in hydrothermal veins and hot springs. It is commonly found in large massive crystalline forms rather than distinct crystals.

Uses & applications

Primarily used as a decorative stone, for carving figurines, in jewelry (beads/cabochons despite softness), and highly valued by mineral collectors and metaphysical practitioners.

Geological facts

Blue Calcite is known for being extremely soft and can be easily scratched by a copper coin. Much of the world's high-quality blue calcite is sourced from Madagascar and Mexico.

Field identification & locations

Identify in the field by its characteristic rhombohedral cleavage, its softness, and its reaction (effervescence) when a drop of diluted hydrochloric acid is applied. It often has a slightly 'soapy' or waxy feel compared to quartz.