A white insoluble compound, BaCO3; r.d. 4.43. It decomposes on heating to give barium oxide and carbon dioxide:BaCO3(s) → BaO(s)+CO2(g) The compound occurs naturally as the mineral witherite and can be prepared by adding an alkaline solution of a carbonate to a solution of a barium salt. It is used as a raw material for making other barium salts, as a flux for ceramics, and as a raw material in the manufacture of certain types of optical glass.
BaCO3(s) → BaO(s)+CO2(g)