Saltpeter, also called niter, is a mineral known to chemists as potassium nitrate. It occurs in limestone caves. Industry uses saltpeter to prepare matches, gunpowder, explosives, and fertilizers. Chemists use it as a reagent in analytical chemistry. It is also used as an oxidizer in liquid rocket fuel propellants.
Saltpeter occurs as colorless or white crystals or crystalline powder. It dissolves in water and melts at about 337 °C (639 °F). Saltpeter is manufactured by reacting potassium chloride with sodium nitrate or nitric acid.
The name saltpeter also refers to other minerals. The most important is Chile saltpeter, which is composed of sodium nitrate. It is used to make fertilizer, nitric acid, and potassium nitrate. Lime saltpeter, or Norwegian saltpeter, is calcium nitrate. It is made from limestone, and is used to make fertilizer, matches, explosives, and other chemicals. Barium nitrate is sometimes known as barya saltpeter. It is used to make barium oxide and green fireworks.
