Carbonates are a group of chemical compounds that contain the carbonate ion, which is a polyatomic anion with the formula CO3^2-. Carbonates can be salts of carbonic acid or carbonate minerals. Here are some key points about carbonates:

• Carbonate is a moderately strong base, so it attracts protons in aqueous solutions. It carries a formal charge of -2 and bonds to metal cations, generally forming insoluble compounds/Descriptive_Chemistry/Main_Group_Reactions/Compounds/Carbonates).
• The most common carbonate minerals are calcite or calcium carbonate, CaCO3, which is the chief constituent of limestone, and aragonite.
• Carbonates are transparent, lightly-colored with a white streak, have average to above-average specific gravity, are soft with good to perfect cleavage, and are soluble in acidic solutions.
• Inorganic carbonates are salts of carbonic acid (H2CO3), containing the carbonate ion, CO2/3-, and ions of metals such as sodium or calcium. They comprise many minerals and are the principal constituents of limestones and dolomites.

Overall, carbonates are an important group of compounds in chemistry and geology, with a wide range of practical applications.