Cobaltous Carbonate, CoCO₃

When cobalt chloride is heated to 140° C. with a solution of sodium hydrogen carbonate saturated with carbon dioxide, anhydrous Cobaltous Carbonate, CoCO₃, is produced as a bright red crystalline powder. By carrying out the reaction at a low temperature the hexahydrate, CoCO₃.6H₂O, is formed as small crystals. A third hydrate, namely, 3CoCO₃.2H₂O, is apparently produced when the hexahydrate is maintained at 20.25° C. in contact with the saturated solution.