mineral

Orange Calcite

Calcium Carbonate (CaCO3)

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

Identified March 25, 2026More mineral →

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Physical properties

Formation & geological history

Formed through sedimentary processes, often as a chemical precipitate from calcium-rich waters or in hydrothermal veins and marine environments. It can occur in deposits spanning various geological ages from the Precambrian to the present.

Uses & applications

Used primarily for ornamental purposes, lapidary work (carvings and spheres), metaphysical collecting, and as a source of lime in the chemical industry.

Geological facts

Calcite is unique for its double refraction (birefringence) property. While common in white or clear, the orange variety gets its color from tiny inclusions of hematite or iron oxide. It is highly reactive to cold dilute hydrochloric acid, which causes it to effervesce (fizz).

Field identification & locations

Identify in the field by its softness (can be scratched by a copper penny) and its characteristic rhombohedral 'leaning box' cleavage planes. Commonly found in Mexico, Brazil, and the USA (Utah).