Calcium Carbonate

Calcium Carbonate, CaCO₃, is a water insoluble, acid soluble, calcium salt that most people encounter everyday. It can be found in sedimentary rock, limestone, marble, chalk, pearls, egg shells, animal shells, and vegetables with dark green colors (such as kale).

Calcium carbonate can form or be created in 3 main ways: synthesized chemically, geologically, or by gradual hardening and collecting of calcium carbonate from the shells of dead organisms. In dissolved in acid, calcium carbonate releases carbon dioxide gas.

Calcium Carbonate has many applications including: construction raw material, iron purification, drilling mud, as well as food, medicinal, and chemical applications. It is also used in personal care products, paints, sealants, textiles, paper, glazes and fluxes.

Additional Notes:
* The Phoenix Mars Lander has discovered calcium carbonate on Mars, which would require water to create. This implies that the currently barren planet of Mars once has its own seas, lakes, and rivers.
* Aragonite (ortho-rhombic), calcite (trigonal), and vaterite (hexagonal) are the 3 polymorph minerals with the chemical structure CaCO₃.
* Limestone Caves & Caverns: The erosion of calcium carbonate minerals such as limestone via carbonic acid (rain) and sulfuric acid (other) can create caves, caverns, and speleothems.