BARIUM CARBONATE

Barium Carbonate

This material is toxic in its raw state and care needs to be taken with storing and handling. Matte glazes made with high proportions should not be considered food safe.

Notes

Barium carbonate powder is dense and white.

While BaCO2 has a high melting temperature, it will break down readily in a glaze melt (liberating the BaO for glass building). It decomposes even more readily during glaze melting in a reduction atmosphere.

Effects produced when baria is acting as a filler are sometimes mistaken for those of a true baria crystal matte. Such will likely leach toxic BaO (other oxides will opacify or produce a low fire matte i.e. CaO, MgO, Alumina, Zircon).

Barium carbonate produces gases as it decomposes, and these can sometimes cause many pinholes or blisters in glazes.

In art ceramics barium carbonate is popular for the production of classic barium crystal mattes, BaO readily forms crystalline phases during cooling. These are dependent on adequate kiln temperatures, cooling cycle and the chemistry of the host glaze.