Mineral

Blue Calcite

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: Pale blue to light sky blue; Luster: Vitreous to waxy/pearly; Crystal structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral in three directions; Specific gravity: 2.71.

Hardness: 3 on Mohs scale
Color: Pale blue to light sky blue
Luster: Vitreous to waxy/pearly

Identified March 20, 2026More mineral →

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Physical properties

Formation & geological history

Formed through sedimentary processes or as a primary mineral in igneous and metamorphic rocks. It often precipitates from marine organisms or in hydrothermal veins. The geological age varies widely from Precambrian to recently formed deposits.

Uses & applications

Used primarily as decorative carvings, tumbled stones for collectors, and in metaphysical practices. In industrial forms, calcite is used in cement, mortars, and as an agricultural soil treatment.

Geological facts

Calcite is unique for its double refraction property, where light passing through a clear crystal splits into two rays. While blue calcite is sought after for its calming aesthetic, it is chemically identical to common limestone or marble.

Field identification & locations

Identify by its 'soapy' or waxy feel and its reaction to dilute hydrochloric acid (it will fizz). Look for the characteristic rhombohedral cleavage planes. Commonly found in large deposits in Mexico, Brazil, and Madagascar.