mineral

Polished blue calcite (likely)

Calcite, CaCO₃

AI-generated identification · may be incorrect

Pale blue to white, waxy-to-glassy luster, commonly translucent with cloudy banding; Mohs hardness 3, rhombohedral cleavage, non-cubic crystals, specific gravity about 2.71. The rounded form appears tumbled or polished.

Identified August 16, 2026More mineral →

Explore Polished blue calcite (likely) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Calcite forms when calcium-carbonate-rich fluids precipitate in veins, caves, and sedimentary rocks; blue coloration may result from trace impurities or inclusions. Calcite occurs from Precambrian to recent geological ages.

Uses & applications

Used for construction aggregate, cement, lime, and optical applications; attractive blue material is mainly sold as a decorative or metaphysical tumbled stone.

Geological facts

Calcite effervesces vigorously with dilute hydrochloric acid and shows strong birefringence—printed text may appear doubled through a clear fragment.

Field identification & locations

Confirm with a steel nail or copper coin (it scratches calcite) and acid testing on an inconspicuous spot. Common sources include Mexico, Madagascar, Brazil, and the United States; the photograph could also represent blue aragonite or dyed calcite.