Specification :

Barium sulfate is a white crystalline solid with the chemical formula BaSO4. It is insoluble in water and other traditional solvents but is soluble in concentrated sulfuric acid. The mineral barite is composed largely of barium sulfate and is a common ore of barium. It is often extracted in a blast furnace, as it can cope with high temperature.
Other uses
Barium sulfate is used as a filler in plastics and as a component of oil well drilling fluid to increase the density. It is also used in Episal salt, brake linings, anacoustic foams, powder coatings, and root canal filling.
Barium sulfate is also used during the procedure of the soil pH test. In this test it is used so that it precipitates out any particles ( usually clay particles) which would otherwise cloud solution preventing one from seeing the colour of the pH indicator I. E. The result of the test.
In colorimetry barium sulfate is used as a near-perfect diffuser when measuring light sources.
In photography it is used as a coating for certain photographic papers.
In metal casting, the moulds used are often coated with barium sulfate in order to prevent the molten metal from bonding with the mould.