mineral

Calcite on Matrix

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale. Color: White to pale tan/translucent. Luster: Vitreous to pearly. Crystal structure: Trigonal/Rhombohedral. Cleavage: Perfect rhombohedral in three directions.

Hardness: 3 on Mohs scale
Color: White to pale tan/translucent
Luster: Vitreous to pearly

Identified July 6, 2026More mineral →

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Physical properties

Hardness: 3 on Mohs scale. Color: White to pale tan/translucent. Luster: Vitreous to pearly. Crystal structure: Trigonal/Rhombohedral. Cleavage: Perfect rhombohedral in three directions.

Formation & geological history

Formed through chemical precipitation in sedimentary environments or as secondary minerals in igneous rock cavities. Common in limestone and marble formations.

Uses & applications

Used primarily as an ornamental specimen for collectors and in the production of cement and lime for the construction industry.

Geological facts

Calcite is famous for its double refraction property and its rapid effervescence (fizzing) when in contact with dilute hydrochloric acid.

Field identification & locations

Identify in the field by its characteristic rhombohedral cleavage and softness (can be scratched by a copper penny). It is one of the most common minerals on Earth.