Calcium Carbonate

Calcium carbonate is a chemical compound with the chemical formula CaCO3. It is a common substance found in rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skeletons and pearls. Materials containing much calcium carbonate or resembling it are described as calcareous. Calcium carbonate is the active ingredient in agricultural lime and is produced when calcium ions in hard water react with carbonate ions to form limescale. It has medical use as a calcium supplement or as an antacid, but excessive consumption can be hazardous and cause hypercalcemia and digestive issues.
Calcium carbonate plays an important role in construction, be it as a building material (marble) or as an ingredient in cement. It is used in medicinal industries which manufacture antacids, tablets which are made of base materials etc. It is used as calcium supplement. It is used in the manufacture of paints, paper, plastics, etc.