mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: Pale orange to deep honey-orange; 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 orange to deep honey-orange
Luster: Vitreous to waxy

Identified June 30, 2026More mineral →

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Physical properties

Formation & geological history

Formed primarily through sedimentary processes such as the precipitation of calcium-rich groundwater or in hydrothermal veins. It is common in limestone and marble formations across various geological eras.

Uses & applications

Used in the manufacture of cement and lime, as an acid neutralizer in the chemical industry, in soil conditioners, and widely as a decorative stone for lapidary work and metaphysical collecting.

Geological facts

Calcite is unique for its property of double refraction (birefringence), where light passing through a clear crystal splits into two rays. Orange calcite specifically is often acid-washed to give it a smooth, waxy surface feel popular for handling.

Field identification & locations

Identify in the field by its rhombohedral cleavage (it breaks into slanted cubes) and its reaction to cold dilute hydrochloric acid (it will effervesce or fizz). It is significantly softer than quartz and can be scratched by a copper coin.