mineral

Blue Calcite

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale. Color: Pale blue to sky blue. Luster: Vitreous to waxy. Crystal System: Trigonal. Cleavage: Perfect rhombohedral. Specific Gravity: 2.71.

Hardness: 3 on Mohs scale
Color: Pale blue to sky blue
Luster: Vitreous to waxy

Identified July 11, 2026More mineral →

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Physical properties

Hardness: 3 on Mohs scale. Color: Pale blue to sky blue. Luster: Vitreous to waxy. Crystal System: Trigonal. Cleavage: Perfect rhombohedral. Specific Gravity: 2.71.

Formation & geological history

Formed through sedimentary processes, primarily from the shells of marine organisms or as a chemical precipitate in warm, shallow sea waters. It often occurs in massive form rather than distinct crystals in this color variety.

Uses & applications

Mainly used as a decorative stone, in lapidary for carvings/beads, and extensively in the metaphysical/collecting community. Industrially, calcite is used in cement and lime.

Geological facts

Blue calcite is known for its soft, 'soapy' or waxy feel due to its low hardness. Large deposits are found in Mexico and Madagascar. It is a common component of marble and limestone.

Field identification & locations

Identify by its pale blue color, waxy luster, and softness (it can be scratched by a copper coin or a steel knife). It will react and effervesce if exposed to a drop of dilute hydrochloric acid (or vinegar).