mineral

Blue calcite (probable)

Calcite, calcium carbonate (CaCO₃)

AI-generated identification · may be incorrect

Pale blue, translucent to opaque mineral with a vitreous to pearly luster and prominent rhombohedral cleavage; Mohs hardness 3, so it scratches easily with a knife. The color and irregular cleavage surfaces are consistent with blue calcite, though visual identification alone is not definitive.

Identified August 9, 2026More mineral →

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Physical properties

Formation & geological history

Usually forms in hydrothermal veins, cavities, and sedimentary carbonate rocks when calcium-rich fluids precipitate calcite. Blue coloration commonly results from trace elements or inclusions; the specimen’s geological age cannot be determined from the photograph.

Uses & applications

Used chiefly as a collector’s mineral, ornamental stone, and occasional lapidary material; calcite is also important industrially in cement, lime, aggregate, and agricultural soil treatment.

Geological facts

Calcite effervesces strongly with dilute hydrochloric acid or vinegar, though vinegar may react slowly. It commonly shows double refraction and is softer than quartz.

Field identification & locations

Commonly found in limestone, marble, veins, and vugs worldwide, including Mexico, the United States, Brazil, and China. Confirm with a hardness test, cleavage, and acid reaction; avoid damaging valuable specimens.