Orange Calcite

Physical Properties

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

Formation & Geological History

Formed through sedimentary processes or hydrothermal precipitation in veins and cavities. It can also occur in metamorphic environments like marble. Most specimens are from the Phanerozoic eon.

Uses & Applications

Used primarily for ornamental carvings, jewelry (rarely due to low hardness), spiritual/metaphysical collecting, and as a source of calcium in industrial chemical processes.

Geological Facts

Orange calcite is often treated with a mild acid bath by dealers to give it a smooth, 'soapy' or waxy feel. It is one of the most common minerals on Earth's crust in its various forms.

Field Identification & Locations

Identify in the field by its 3-way rhombohedral cleavage and its rapid effervescence (bubbling) when a drop of cold dilute hydrochloric acid is applied. Commonly found in Mexico, Brazil, and the USA.

Identified on: 5/15/2026

Mode: Standard