In nature, barium nitrate is found in the mineral nitrobarite, which forms clear, colourless crystals. A white, crystalline powder is commercially available, which is only moderately soluble in cold water. When heated to 100 °C, the solubility increases by about three times. Barium nitrate is hygroscopic, it attracts water from the air. When heated above the melting point, it decomposes with green glow to oxygen, barium peroxide, nitrogen and nitrogen monoxide. Mixtures with coal, sulphur and other flammable substances are explosive. Mixtures with metal powders are particularly dangerous because they can explode by friction alone. Pyrotechnic mixtures show an intense green flame colour when burning.
It is prepared by reacting a barium carbonate or barium sulfide solution with nitric acid. If barium carbonate is used, water and carbon dioxide are formed as by-products:
BaCO3 + 2 HNO3 → Ba(NO3)2 + H2 + O + CO2
In chemistry lessons, barium nitrate is often used to demonstrate the green flame colouring.
Pyrotechnics need barium nitrate for green fireworks or for the production of sparklers. Occasionally, it is still used as an oxidizing agent in the primers for rifle cartridges.