mineral

Blue Calcite

Calcite (Calcium Carbonate, CaCO3)

Hardness: 3 on Mohs scale; Color: Pale blue to sky blue; Luster: Vitreous to pearly/waxy; Crystal Structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral in three directions; Specific Gravity: 2.71

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

Identified June 22, 2026More mineral →

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Physical properties

Formation & geological history

Formed through sedimentary processes, often precipitated from marine environments or in hydrothermal veins and hot springs. Many specimens are found in limestone deposits.

Uses & applications

Used primarily as decorative stones, in metaphysical practices, and occasionally in cement manufacturing or as an acid neutralizer in chemical industries.

Geological facts

Calcite is the most common form of calcium carbonate. The blue variety gets its distinctive hue from trapped inclusions during formation, though the exact nature of the blue color center is still a subject of scientific debate among mineralogists.

Field identification & locations

Identify by its 'waxy' texture and the fact that it can be scratched by a copper coin. It will effervesce (fizz) if a drop of diluted hydrochloric acid is applied. Major sources include Mexico and Madagascar.