|Atomic mass||137.33 amu|
Barium was discovered in 1808. Shown in the right is a sample of barium in argon. Storing barium in argon minimizes oxidation of the sample.
Gem-quality baryte are mined in South Dakota, and Arizona. Other good specimens of baryte are found in England, Italy, Sardinia, and the Sahara desert.
Barium is mainly used in:
- medical procedure. Because barium sulfate, BaSO4, is opaque to x-rays, it is used in x-ray diagnoses of gastrointestinal examinations. The patient drinks a "barium cocktail", a suspension of BaSO4 in water, to outline the stomach and intestines for X-ray examination. Although all soluble barium salts are toxic, the procedure is safe because BaSO4 is essentially insoluble.
- firework displays. Barium nitrate, Ba(NO3)2, gives fireworks a green colour.