Calcium bicarbonate is a chemical compound with the formula Ca(HCO₃)₂. It is commonly found in natural water sources, where it forms when carbon dioxide dissolves in water containing calcium carbonate. This compound plays a significant role in the hardness of water and can affect its taste and quality. In its solid form, calcium bicarbonate is not stable and typically exists in solution. When heated, it decomposes into calcium carbonate, water, and carbon dioxide. This process is important in various natural and industrial applications, including water treatment and the formation of limestone in geological processes.