mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: bright orange to honey amber; Luster: Vitreous to waxy; Crystal Structure: Trigonal/Hexagonal; Cleavage: Perfect rhombohedral in three directions; Specific Gravity: 2.71

Hardness: 3 on Mohs scale
Color: bright orange to honey amber
Luster: Vitreous to waxy

Identified March 23, 2026More mineral →

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Physical properties

Formation & geological history

Formed through sedimentary processes such as precipitation from calcium-rich solutions or in hydrothermal veins. Often found in limestone caves or as a secondary mineral in igneous and metamorphic rocks. Most commercial orange specimens date from various Phanerozoic periods.

Uses & applications

Predominantly used for ornamental purposes, lapidary work (cabochons), carvings, and as a popular metaphysical or decorative stone for collectors.

Geological facts

Orange calcite is known for its 'acid-wash' appearance when treated; most commercial specimens are dipped in a weak acid to give them a smooth, waxy feel and eliminate white bruising on the surface.

Field identification & locations

Identify in the field by its softness (can be scratched by a copper penny) and its reaction to cold dilute hydrochloric acid, which causes it to effervesce vigorously. Common locations include Mexico, Utah (USA), and Brazil.