mineral

Blue Calcite

Calcite (Calcium Carbonate, CaCO3)

Hardness: 3 on Mohs scale; Color: Pale sky blue to turquoise blue; Luster: Vitreous to waxy; Crystal Structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral in three directions; Specific Gravity: 2.71

Hardness: 3 on Mohs scale
Color: Pale sky blue to turquoise blue
Luster: Vitreous to waxy

Identified April 6, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling or evaporation of calcium-rich solutions in sedimentary environments or hydrothermal veins. It is a common component of limestone and marble, often taking on blue hues due to metal inclusion or irradiation.

Uses & applications

Commonly used as a decorative stone, in lapidary work for cabochons and carvings, and widely sold as a 'healing' or metaphysical crystal.

Geological facts

Calcite is famous for having one of the widest varieties of crystal shapes among all minerals. Blue Calcite specifically is often acid-washed to give it a characteristic smooth, waxy feel that enthusiasts enjoy.

Field identification & locations

Identified in the field by its softness (can be scratched by a copper coin) and its strong effervescence when exposed to cold dilute hydrochloric acid. It is commonly found in large deposits in Mexico and Madagascar.