The carbonate ion, represented as CO3^2-, is a polyatomic ion composed of one carbon atom and three oxygen atoms. It carries a negative charge of two, which means it can easily bond with positively charged ions, forming various compounds. Carbonate is commonly found in nature, especially in minerals like calcite and dolomite, and plays a crucial role in the carbon cycle. In addition to its natural occurrence, CO3^2- is important in many biological and chemical processes. For example, it is a key component in the formation of calcium carbonate, which is essential for the shells of marine organisms. Carbonate ions also help regulate pH levels in aquatic environments, making them vital for maintaining healthy ecosystems.