Barium nitrate Barium nitrate Barium nitrate is the inorganic compound with the chemical formula Ba(NO). It, like most barium salts, is colorless, toxic, and water-soluble. It burns with a green flame and is an oxidizer; the compound is commonly used in pyrotechnics. Barium nitrate is manufactured by two processes that start with the main source material for barium, the carbonate. The first involves dissolving barium carbonate in nitric acid, allowing any iron impurities to precipitate, then filtered, evaporated, and crystallized. The second requires combining barium sulfide with nitric acid. It occurs naturally as the very rare mineral "nitrobarite". At elevated temperatures, barium
Calamine brass Calamine brass Calamine brass is brass produced by a particular alloying technique using the zinc ore calamine directly, rather than first refining it to metallic zinc. Direct zinc smelting appears to have been unknown in Europe until the mid-18th century, even though the alloyed calamine brass was in use for centuries, and metallic zinc was produced directly via reducing-atmosphere smelting in India and China from the 12th century CE onwards. Brass is an alloy of copper and zinc and, when it was first developed, methods for producing metallic zinc were unknown. Metallurgists wishing to produce brass thus used calamine (actually