mineral

Tumbled blue calcite

Calcite (CaCO₃), likely blue calcite variety

AI-generated identification · may be incorrect

Typically pale blue to lavender, cloudy, and waxy to vitreous; Mohs hardness 3, rhombohedral crystal structure, perfect rhombohedral cleavage, and specific gravity about 2.71. The rounded shape and matte surface indicate tumbling or polishing.

Identified August 17, 2026More mineral →

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Physical properties

Formation & geological history

Blue calcite forms in carbonate veins, cavities, and sedimentary limestone environments, with color commonly caused by trace impurities or inclusions. The specimen’s geological age cannot be determined visually and depends on its deposit.

Uses & applications

Used mainly as a decorative or metaphysical collectible; calcite is also important industrially in cement, lime, aggregate, and optical-grade applications. This piece is too small and cloudy for conventional gemstone use.

Geological facts

Calcite effervesces readily with dilute hydrochloric acid and may scratch easily with a steel knife. Blue calcite is often confused with blue aragonite, celestite, or dyed chalcedony.

Field identification & locations

Common sources include Mexico, Madagascar, Brazil, and the United States. Field tests include very low hardness, rhombohedral cleavage in a broken fragment, and strong acid reaction; avoid acid testing on a finished specimen.