Properties
| Category | Carbonate mineral |
|---|---|
| Formula | CaCO3 |
| Crystal system | Trigonal |
| Color | Typically colorless or creamy white - may have shades of brownish colors |
| Crystal habit | Botryoidal, concretionary, druse, globular, granular, massive, rhombohedral, scalenohedral, stalactitic |
| Cleavage | Perfect on {1011} three directions with angle of 74° 55' |
| Fracture | Conchoidal |
| Tenacity | Brittle |
| Mohs scale hardness | 3 (defining mineral) |
| Luster | Vitreous to pearly on cleavage surfaces |
| Streak | White |
| Diaphaneity | Transparent to translucent |
| Specific gravity | 2.71 |
From the Wikipedia article
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on scratch hardness comparison. Large calcite crystals are used in optical equipment, and limestone composed mostly of calcite has numerous uses.
Source
Source record: crystal-compendium/calcite/minerals.json. Fetched from English Wikipedia by the operator 2 October 2026.
https://en.wikipedia.org/wiki/Calcite — revision id 1369611712. Text and properties from Wikipedia, licensed CC BY-SA 4.0.