mineral
Calcite
Calcium Carbonate (CaCO3)
AI-generated identification · may be incorrectHardness: 3 on Mohs scale; Color: White/off-white; Luster: Vitreous to pearly; Crystal structure: Trigonal/Rhombohedral cleavage; Cleavage: Perfect rhombohedral in three directions; Specific gravity: 2.71
- Hardness
- 3 on Mohs scale
- Color
- White/off-white
- Luster
- Vitreous to pearly
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: White/off-white; Luster: Vitreous to pearly; Crystal structure: Trigonal/Rhombohedral cleavage; Cleavage: Perfect rhombohedral in three directions; Specific gravity: 2.71
Formation & geological history
Formed through sedimentary precipitation in marine environments, hydrothermal veins, or as a constituent of metamorphic marble. It is the primary mineral in limestone and marble.
Uses & applications
Used in the manufacture of cement and mortar, as a soil conditioner in agriculture, a flux in glassmaking, and clear varieties (Iceland Spar) are used in optical instruments.
Geological facts
Calcite is famous for its double refraction (birefringence), where an object viewed through a clear crystal appears doubled. It is the primary component of stalactites and stalagmites in caves.
Field identification & locations
Identify in the field by its 3-way rhombohedral cleavage and its strong effervescence (bubbling) when exposed to cold dilute hydrochloric acid or vinegar. Common worldwide, especially in limestone regions.
