mineral

Blue calcite sphere

Calcite (CaCO₃), commonly blue-calcite variety

AI-generated identification · may be incorrect

Typically pale to medium blue with cloudy zones, vitreous to pearly luster, and transparent to translucent appearance; Mohs hardness 3, rhombohedral crystal structure, perfect rhombohedral cleavage, and specific gravity about 2.71. The spherical polish is human-made.

Identified August 8, 2026More mineral →

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Physical properties

Formation & geological history

Blue coloration generally results from trace impurities or structural defects in calcite formed in hydrothermal veins, carbonate cavities, or metamorphosed limestone; ages range from recent to hundreds of millions of years depending on the deposit.

Uses & applications

Used primarily for décor, meditation objects, and mineral collecting; too soft for durable jewelry or construction aggregate. It reacts strongly with dilute hydrochloric acid, producing effervescence.

Geological facts

Calcite is one of the most common carbonate minerals and is strongly birefringent, producing double refraction in clear crystals. Blue calcite is often confused with blue aragonite or dyed chalcedony.

Field identification & locations

Identify by its softness, rhombohedral cleavage, acid reaction, and cloudy blue color; common sources include Mexico, Madagascar, Argentina, and parts of the United States. A photo cannot confirm the variety, and some commercial spheres may be dyed.