mineral

Calcite

Calcium Carbonate (CaCO3)

AI-generated identification · may be incorrect

Hardness: 3 on Mohs scale; Color: White, colorless, grey, yellow, green; Luster: Vitreous to earthy; Crystal structure: Trigonal; Cleavage: Perfect rhombohedral in three directions; Specific gravity: 2.71

Hardness: 3 on Mohs scale
Color: White, colorless, grey, yellow, green
Luster: Vitreous to earthy

Identified August 3, 2026More mineral →

Explore Calcite in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed through the precipitation of calcium carbonate from solution in marine, hydrothermal, or cave environments, spanning various geological ages.

Uses & applications

Used in the manufacture of cement, lime, agriculture soil treatment, construction materials, and optical equipment.

Geological facts

Calcite exhibits strong double refraction (birefringence), where objects viewed through clear crystals appear doubled.

Field identification & locations

Easily identified by its characteristic rhombohedral cleavage and strong effervescence (fizzing) when exposed to dilute hydrochloric acid. Found worldwide in sedimentary, metamorphic, and igneous settings.