Discovered in 1808 by Sir Humphry Davy, barium is a silvery-white element with an atomic number of 56. It was identified in 1774 by Carl Scheele, but the technology of the time did not allow him to isolate it. Barium was named after the Greek word for "heavy." Its melting point is 1,341 degrees Fahrenheit, with a boiling point of 3,447 degrees Fahrenheit.
Barite, the mineral from which barium is isolated, was found to have unusual qualities as early as the 1600s. Vincentius Casciorolus noticed that when the mineral was combusted and exposed to sunshine, it would glow. Eventually, barite was widely known by alchemists as the Bologna Stone.
Barium has a dark grey coating when it oxidizes. As 0.0425 percent of the Earth's crust, barium is an alkaline earth metal. It is used enhance X-ray technology and remove gases from vacuum tubes. It is combined with nickle to create an alloy in spark plug wires, and it is added to cast iron and steel. California's official gemstone, benitoite, is a fluorescent-blue gem that contains barium.
Barium is not a carcinogen, but breathing it in can cause build up in the lungs. This leads to a condition called baritosis, but the condition is benign and clears after a time without exposure to barium.