mineral

Blue Calcite

Calcium Carbonate (CaCO3)

AI-generated identification · may be incorrect

Hardness: 3 on Mohs scale; Color: Pale blue to sky blue; Luster: Vitreous to pearly; Crystal structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral

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

Identified July 9, 2026More mineral →

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Physical properties

Hardness: 3 on Mohs scale; Color: Pale blue to sky blue; Luster: Vitreous to pearly; Crystal structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral

Formation & geological history

Formed in sedimentary environments through chemical precipitation or in metamorphic settings as marble. The blue color often comes from tiny inclusions or structural defects in the crystal lattice during formation.

Uses & applications

Primarily used as a decorative stone, in lapidary work for cabochons and carvings, and as a popular specimen for metaphysical collectors.

Geological facts

Blue calcite is known for its relatively soft nature, making it popular for beginners to practice stone carving. It often has a slightly waxy feel when polished.

Field identification & locations

Look for its characteristic rhombohedral cleavage and softness (can be scratched by a copper penny). It will react and effervesce if exposed to weak hydrochloric acid. Common in Mexico and Madagascar.