mineral

Clear Calcite

Calcite (Calcium Carbonate, CaCO3)

Hardness: 3 on Mohs scale; Color: Colorless to white; Luster: Vitreous to pearly; Crystal Structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral in three directions.

Hardness: 3 on Mohs scale
Color: Colorless to white
Luster: Vitreous to pearly

Identified July 7, 2026More mineral →

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Physical properties

Hardness: 3 on Mohs scale; Color: Colorless to white; Luster: Vitreous to pearly; Crystal Structure: Trigonal/Rhombohedral; Cleavage: Perfect rhombohedral in three directions.

Formation & geological history

Forms through sedimentary precipitation in marine environments, hydrothermal veins, and as a primary mineral in igneous carbonatites. It is the main component of limestone and marble.

Uses & applications

Used in the manufacture of cement and mortar, as a soil conditioner in agriculture, in the optical industry (high-grade Iceland Spar), and as a collector specimen.

Geological facts

Calcite is famous for its double refraction (birefringence), where light passing through a clear crystal splits into two rays, making objects viewed through it appear doubled.

Field identification & locations

Identify in the field by its 3-way rhombohedral cleavage and its strong effervescent reaction (fizzing) when exposed to weak hydrochloric acid or vinegar.