Carbonate
In chemistry, a
carbonate is a salt of carbonic acid, characterized by the presence of the
carbonate ion, CO2− 3. The name may also mean an ester of carbonic acid, an organic compound containing the
carbonate group C2. The term is also used as a verb, to describe carbonation: the process of raising the concentrations of carbonate and bicarbonate ions in water to produce carbonated water and other carbonated beverages — either by the addition of carbon dioxide gas under pressure, or by dissolving carbonate or bicarbonate salts into the water. In geology and mineralogy, the term "carbonate" can refer both to carbonate minerals and carbonate rock, and both are dominated by the carbonate ion, CO2− 3. Carbonate minerals are extremely varied and ubiquitous in chemically precipitated sedimentary rock. The most common are calcite or calcium carbonate, CaCO3, the chief constituent of limestone; dolomite, a calcium-magnesium carbonate CaMg2; and siderite, or iron carbonate, FeCO3, an important iron ore. Sodium carbonate and potassium carbonate have been used since antiquity for cleaning and preservation, as well as for the manufacture of glass.