The first instance of uranium mining was in 1790 at the Sankt Joachimsthal mine, located on the border between Bohemia and Saxony (in what is now the Czech Republic). The mine was originally opened as a silver mine, and for many years the miners had encountered a black, shiny mineral which they dubbed “pechblende” — pech meaning “bad luck” and blende meaning “mineral.” Today we know this mineral as pitchblende, a uranium-rich oxide.
The first complete analysis of pitchblende was performed by the self-educated German chemist Martin Klaproth in 1789. He was able to isolate the oxide and referred to it as “a strange kind of half-metal.” In 1841, the French chemist Eugene Peligot was able to extract uranium in its metallic form. Later, in 1870, uranium was established to be the heaviest element naturally present on Earth, as demonstrated by the Russian chemist Dimitri Mendeleev in his periodic table.
For half a century after Klaproth’s discovery, the main application of uranium was to produce colourful and vivid fluorescent glass, known as Bohemian glass. This glass was highly sought after, and its production rejuvenated the Joachimsthal mine. Interestingly, the production of Bohemian glass was a closely guarded secret — long before the secretive uranium science of the 1940s.
The period between 1895 and 1938 is sometimes described as the birth period of nuclear science. It began with Rontgen’s discovery of X-rays in 1895, followed by Henri Becquerel’s discovery of radioactivity in uranium in 1896, the work of Marie and Pierre Curie, and culminated with Hahn and Strassmann chemically proving nuclear fission in 1938. The realisation of the potential of fission, coinciding with the Second World War, gave rise to a massive increase in uranium prospecting and mining worldwide.
Nowadays, uranium is mined primarily as part of the nuclear fuel cycle, fuelling approximately 440 power reactors operating around the world.