The chemical formula for calcium carbonate is CaCO₃. This compound is formed from one calcium atom (Ca), one carbon atom (C), and three oxygen atoms (O). It naturally occurs in various minerals, including calcite and aragonite, and is a major component of shells in marine organisms and limestone. Calcium carbonate is widely used in industries such as construction, where it serves as a building material, and in agriculture as a soil amendment to reduce acidity. It also plays a significant role in the carbon cycle, acting as a carbon sink and in geological formations.