Magnesium oxide is produced by the calcination of magnesium carbonate or magnesium hydroxide. Calcite is an ionic salt called calcium carbonate or CaCO. Stony corals secrete massive calcium carbonate exoskeletons. Lithium chloride is produced by treatment of lithium carbonate with hydrochloric acid. Kelp is dried with calcium chloride for use in producing sodium carbonate. Monopotassium phosphate is produced by the action of phosphoric acid on potassium carbonate. Calcium carbonate shares the typical properties of other carbonates. These solutions contained a range of concentrations of sodium, chloride, potassium, carbonate, phosphate, and hydroxide. Carbonation occurs on rocks which contain calcium carbonate, such as limestone and chalk. Alkaline (higher) pH favors formation of carbonate and phosphate calculi. Increasing pressure also increases the solubility of calcium carbonate. The crystal structure is made up of copper, carbonate and hydroxide ions. Fluctuating sea levels compressed numerous layers of calcium carbonate, sand, and shells. Typical bases are triethylamine, potassium carbonate, and sodium acetate. The excess of boron trichloride was quenched in a mixture of potassium carbonate and methanol.