Barium carbonate

Barium carbonate is a chemical compound. Its chemical formula is BaCO3. It contains barium and carbonate ions.
Properties.
Barium carbonate is a white solid. It does not dissolve in water. It reacts with acids to make barium salts. It turns into barium oxide and carbon dioxide when heated. It reacts with sulfuric acid to make barium sulfate though.
Occurrence.
Barium carbonate occurs as witherite. Witherite is the main source of barium salts. It is more easily turned into other barium compounds than barium sulfate, barite. It is heavily mined in Northumberland. It turns into barium sulfate when water containing sulfates flows through it.
Preparation.
It can be purified from the natural ore, or it can be made by reacting barium sulfide with sodium carbonate. It can also be made by reacting barium sulfide with a mixture of carbon dioxide and water.
Uses.
Barium carbonate is used to poison rats. It is also used in making bricks. It is also used to glaze ceramics. This glaze can make different colors.
Safety.
Barium carbonate can dissolve in stomach acid, so it is toxic. There is a controversy over whether it should be used as a glaze.