mineral

Blue-green calcite (likely), possibly pale aragonite

Calcite, CaCO₃

AI-generated identification · may be incorrect

Pale blue-green, cloudy and roughly crystalline with a vitreous-to-pearly luster; calcite has Mohs hardness 3, perfect rhombohedral cleavage, and specific gravity about 2.71. The specimen appears naturally fractured or cleaved rather than polished.

Identified August 20, 2026More mineral →

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Physical properties

Formation & geological history

Likely formed by precipitation from carbonate-rich groundwater or hydrothermal fluids, commonly in veins, cavities, and sedimentary settings; its exact geological age cannot be determined from the image. Blue-green color may result from copper or other trace impurities.

Uses & applications

Used mainly as a collector specimen, ornamental stone, or metaphysical material; calcite is also important industrially in cement, lime, aggregate, and chemical production. This rough piece has limited commercial value.

Geological facts

Calcite strongly effervesces with dilute hydrochloric acid or household vinegar, though vinegar may react slowly. It commonly shows rhombohedral cleavage and may display double refraction through transparent areas.

Field identification & locations

Test cautiously for fizz with acid, softness, and cleavage; avoid confusing it with harder blue-green quartz or fluorite. Calcite occurs worldwide, including Mexico, the United States, Iceland, and China.