mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: bright orange to peach; Luster: vitreous to waxy; Crystal structure: trigonal/hexagonal; Cleavage: perfect in three directions (rhombohedral); Specific gravity: 2.71

Hardness: 3 on Mohs scale
Color: bright orange to peach
Luster: vitreous to waxy

Identified May 27, 2026More mineral →

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Physical properties

Hardness: 3 on Mohs scale; Color: bright orange to peach; Luster: vitreous to waxy; Crystal structure: trigonal/hexagonal; Cleavage: perfect in three directions (rhombohedral); Specific gravity: 2.71

Formation & geological history

Formed through chemical precipitation from calcium-rich solutions or in sedimentary environments. Orange hues are often caused by inclusions of hematite or other iron oxides during formation.

Uses & applications

Used primarily as decorative stones, in lapidary work for carvings or polished palm stones, as a source of lime in chemical industries, and popular in metaphysical crystal collections.

Geological facts

Orange calcite is known for its 'acid test' reaction, where it effervesces (fizzes) when a drop of cold dilute hydrochloric acid is applied. It is also often fluorescent under UV light.

Field identification & locations

Identify in the field by its soft surface (can be scratched by a copper penny or steel) and its typical rhombohedral cleavage. Commonly found in Mexico, Brazil, and the USA.