mineral

Blue calcite (probable)

Calcite, CaCO₃

AI-generated identification · may be incorrect

Pale blue to gray-blue, with a vitreous to pearly luster and commonly cloudy, massive texture; Mohs hardness 3, rhombohedral cleavage, and specific gravity about 2.71. The specimen appears rough and partially crystalline, though the image is not sharp enough for certainty.

Identified September 2, 2026More mineral →

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Physical properties

Formation & geological history

Forms when calcium-carbonate-rich fluids precipitate in cavities, veins, or sedimentary environments; deposits range from ancient to modern geologic ages. Blue color may result from inclusions or trace impurities.

Uses & applications

Used mainly as a collector mineral and occasionally for ornamental carvings; calcite is also important industrially in cement, lime, aggregate, and agriculture.

Geological facts

Calcite effervesces visibly with dilute hydrochloric acid or vinegar when powdered or freshly scratched. It shows strong birefringence—text viewed through a clear fragment may appear doubled.

Field identification & locations

Common localities include Mexico, the United States, Iceland, China, and Peru. Confirm by testing softness against a steel nail or copper coin and checking acid reaction; blue quartz or blue fluorite would be harder or show different cleavage.