Lithium carbonate is an inorganic compound with the chemical formula Li2CO3 and a molecular weight of 73.89. It is a colorless monoclinic crystal, slightly soluble in water and dilute acid, and insoluble in ethanol and acetone. Carbonates with lower thermal stability than other elements of the same group in the periodic table do not deliquesce in the air and can be obtained by adding sodium carbonate to lithium sulfate or lithium oxide solution. When carbon dioxide is introduced into the aqueous solution, it can be converted into acid salt and hydrolyzed by boiling. It is used as a raw material for ceramics, glass, ferrite, lithium batteries, etc., and is used medically to treat depression.