Magnesium oxide (Magnesium oxide, burnt magnesia, periclase, E530) — colorless crystals, insoluble in water. The chemical formula is MgO.
In industry, it is used for the production of refractories, cements, purification of petroleum products, as a filler in the production of rubber.
In medicine, it is used for high acidity of gastric juice, as it is caused by an excessive content of hydrochloric acid. Burnt magnesia is also taken in case of accidental ingestion of acids in the stomach.
It is an absolute reflector-a substance with a reflection coefficient equal to one in a wide spectral band.