Orange Calcite

Physical Properties

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

Formation & Geological History

Formed in sedimentary environments through the chemical precipitation of calcium-rich fluids, or as a secondary mineral in igneous and metamorphic rocks. Often found in limestone caves or as hydrothermal veins.

Uses & Applications

Used as a decorative stone, in lapidary work for carvings or polished stones, and as a source of lime in cement. Highly valued by crystal collectors for its vibrant color.

Geological Facts

Calcite is the most stable polymorph of calcium carbonate. It is famous for its 'double refraction' property, though this is most visible in the clear variety known as Iceland Spar.

Field Identification & Locations

Identified in the field by its soft surface (can be scratched by a copper coin) and its effervescent reaction to dilute hydrochloric acid. Commonly found in Mexico, Brazil, and the USA.

Identified on: 5/13/2026

Mode: Standard