mineral

Orange Calcite

Calcite (Calcium Carbonate - CaCO3)

Hardness: 3 on Mohs scale (relatively soft); Color: Pale orange to honey; Luster: Vitreous to waxy; Crystal structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral in three directions; Specific gravity: 2.71

Hardness: 3 on Mohs scale (relatively soft)
Color: Pale orange to honey
Luster: Vitreous to waxy

Identified March 26, 2026More mineral →

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Physical properties

Formation & geological history

Formed through sedimentary processes, primarily from the shells of marine organisms or precipitation from calcium-rich water in caves (stalactites/stalagmites) and hot springs. It can also occur in metamorphic marble.

Uses & applications

Used widely in the decorative arts for carvings, tumbled stones, and 'metaphysical' retail. Industrially, calcite is used in the manufacture of cement, lime, and as an acid neutralizer in the chemical industry.

Geological facts

Calcite is famous for its optical property called double refraction; if you place a clear crystal over a line, it will appear as two lines. It is the primary mineral found in limestone and marble.

Field identification & locations

In the field, it can be definitively identified by its reaction to dilute hydrochloric acid (it will fizz/effervesce). It is much softer than quartz (which it is often mistaken for) and can be scratched with a copper penny.