Collection: calcite

Crystal system- Trigonal (often displaying rhombohedral cells r scalenohedral habits)

Mineral class- Carnonates
Hardness- 3 on the MOHs scale
Rock formation- Sedimentary (limestone,chalk) Metamorphic(marble) and igneous (carbonatites)

Geological rock formation;
Sedimentary deposition- The most common origin. It precipitates chemically from seawater or accumulated biologically from shell fragments of marine organisms,creating limestone and chalk.
Metamorphism- when limestone is subjected to high heat and pressure deep underground, it recrystallises into marble.
Hydrothermal veins- Dissolved calcium and carbonate ions in hot underground fluids precipitate out into fractures creating thick white mineral veins.
Evaporites and speleothems - Groundwater dripping in caves deposits calcite to form stalactites and travertine.