mineral
Calcite
Calcium Carbonate (CaCO3)
AI-generated identification · may be incorrectHardness: 3 on Mohs scale. Color: Grayish-white, colorless, or smoky. Lustre: Vitreous to pearly. Crystal system: Trigonal/Rhombohedral. Cleavage: Perfect rhombohedral in three directions. Specific Gravity: 2.71.
- Hardness
- 3 on Mohs scale
- Color
- Grayish-white, colorless, or smoky
Identified More mineral →
Explore Calcite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 on Mohs scale. Color: Grayish-white, colorless, or smoky. Lustre: Vitreous to pearly. Crystal system: Trigonal/Rhombohedral. Cleavage: Perfect rhombohedral in three directions. Specific Gravity: 2.71.
Formation & geological history
Formed through sedimentary processes including chemical precipitation from groundwater or marine environments, and as a primary mineral in igneous carbonatites or metamorphic marbles.
Uses & applications
Used as a primary component in cement and mortar, in the production of lime, as a soil conditioner in agriculture, and as a flux in steel manufacture. High-clarity specimens are used in optical instruments.
Geological facts
Calcite exhibits double refraction (birefringence); if you place a clear piece over text, it will appear as two images. It is the primary constituent of limestone and marble.
Field identification & locations
Easily identified in the field by its 3-way rhombohedral cleavage and its vigorous effervescence (bubbling) when a drop of dilute hydrochloric acid is applied. Commonly found in sedimentary basins and cave systems.
