mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: Bright orange to yellowish-orange; Luster: Vitreous to waxy/greasy; Crystal System: Trigonal/Hexagonal; Cleavage: Perfect rhombohedral in 3 directions; Specific Gravity: 2.71

Hardness: 3 on Mohs scale
Color: Bright orange to yellowish-orange
Luster: Vitreous to waxy/greasy

Identified July 24, 2026More mineral →

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Physical properties

Formation & geological history

Forms through chemical precipitation in sedimentary environments, hot springs, and hydrothermal veins. Common in limestone deposits and cave formations where calcium-carbonate-rich fluids deposit layers of calcite. The orange color is often caused by trace inclusions of hematite or iron oxide.

Uses & applications

Popular in lapidary work, carving, mineral collections, and decorative items. Also used industrially in acid neutralization, soil treatment, and manufacturing when crushed into limestone powder.

Geological facts

Calcite exhibits double refraction (birefringence), where light passing through a clear specimen splits into two rays. It reacts vigorously with dilute hydrochloric acid by effervescing (fizzing).

Field identification & locations

Identified in the field by its low hardness (can be scratched easily with a copper penny), soft waxy appearance, rhombohedral cleavage faces, and strong effervescence with weak acids. Commonly found in Mexico, Brazil, Canada, and the USA.