It serves as an antacid and calcium supplement in pharmaceuticals a filler in paper plastics and paints in construction as limestone aggregate or cement raw material and in agriculture for soil pH adjustment.

Its primary purpose is to neutralize acids (CaCO 2H Ca HO CO) provide calcium nutrition and act as a mild abrasive or opacifier due to its insolubility in water (Ksp 3.310).

Calcium carbonate (CaCO3) is a white odorless crystalline powder or colorless solid ionic compound consisting of Ca cations and trigonal planar CO anions most commonly occurring as the mineral calcite with rhombohedral structure and decomposing at 825C.