It is a soft, silvery metal and when cut it quickly turns a black color due to the formation of barium oxide, (BaO). Barium powder can ignite spontaneously in air.īarium sulfate, used in x-ray imaging, is highly insoluble in water, and is therefore nontoxic and completely removed from the digestive tract.īarium is a metallic element chemically resembling calcium but more reactive.

This causes the beaker to freeze to the wooden board.īarium compounds that are water or acid soluble are highly poisonous. As a result, the temperature will drop quickly. The reaction between ammonium thiocyanate and barium hydroxide octahydrate is endothermic. The element was called barium because it was found in barite (barium sulfate) a mineral given its name because of its high density. The experimental details are on our strontium page. This was correct, and Davy isolated strontium in a similar way. Davy followed the advice of Swedish chemist Jacob Berzelius, who had told him that barium sulfate could be decomposed by electrolysis. (2))īarium metal was isolated for the first time in 1808 by English chemist Sir Humphrey Davy in London. (Until this point, people had thought Bologna stone was a compound of calcium. Investigating magnesium oxide in 1774, Scheele found a new earth metal: “an earth differing from all earths hithero known.” He called this new metal ‘terra ponderosa.’ (Latin: heavy earth.)Ī comparison was made with Bologna stone, and the two were found to contain the same substance. Of course, at the time, nobody suspected there were any new elements to be discovered!Ībout 170 years passed before barium was first recognized as a new element by Swedish scientist Carl W. Sadly, also, no-one took the opportunity to discover the new element present in Bologna stone. Rather than ‘philosopher’s stone’ it became known as ‘Bologna stone’ – a curiosity. Sadly for Casciorolus, although this material’s properties were interesting, it proved useless as a means of making gold from other metals and failed to make him immortal. After heating, it became impure barium sulfide, BaS. We now know that the silvery white mineral was impure barium sulfate, BaSO 4. But what really excited Casciorolus – and others – was that if the combusted material was exposed to sunshine, it would glow in the dark for up to an hour afterwards. When the mineral was heated and combusted, its product emitted a phosphorescent red glow – very neat. Perhaps, he thought, it might even be the philosopher’s stone. He had learned there was a heavy, silvery-white mineral with remarkable properties in the mountains near Bologna, Italy. In the early 1600s, Vincentius Casciorolus, a shoemaker with an interest in alchemy, was excited.

Ba element