Uranium tile Uranium tile Uranium tiles have been used in the ceramics industry for many centuries, as uranium oxide makes an excellent ceramic glaze, and is reasonably abundant on the earth's crust. Not long after Henri Becquerel discovered radioactivity in uranium salts, Madame Curie discovered both polonium and radium as two new radioactive elements also present with uranium. The relatively high specific activity and moderate half-life of 1,600 years of Ra-226, the main radioisotope of radium found in uranium ore, made for a material which when mixed with a phosphor allowed for a glow-in-the-dark substance. Thus, in addition to its medical usage,
Decay product ends with an isotope of lead or bismuth. Bismuth itself decays to thallium, but the decay is so slow as to be practically negligible. In many cases, individual members of the decay chain are as radioactive as the parent, but far smaller in volume/mass. Thus, although uranium is not dangerously radioactive when pure, some pieces of naturally occurring pitchblende are quite dangerous owing to their radium-226 content, which is soluble and not a ceramic like the parent. Similarly, thorium gas mantles are very slightly radioactive when new, but become more radioactive after only a few months of storage as the