ETYM Cf. French carbonate.
A salt or ester of carbonic acid.
CO32– ion formed when carbon dioxide dissolves in water; any salt formed by this ion and another chemical element, usually a metal.
Carbon dioxide (CO2) dissolves sparingly in water (for example, when rain falls through the air) to form carbonic acid (H2CO3), which unites with various basic substances to form carbonates. Calcium carbonate (CaCO3) (chalk, limestone, and marble) is one of the most abundant carbonates known, being a constituent of mollusk shells and the hard outer skeletons of crustaceans.

1. To treat with carbon dioxide.
2. To turn into a carbonate.