Pitchblende attained considerable notoriety towards the end of the 19th century on account of two important discoveries.
In 1789 Klaproth isolated from pitchblende a yellow oxide which he viewed as the oxide of a new metal, which he named uranium, after the newly discovered planet of Herschel.
The only practically available raw material for 'the extraction of uranium is pitchblende (q.v.).
Pure pitchblende is U308, which, in relatively good specimens, forms some 80% or more of the whole.
To extract the metal, the pitchblende is first roasted in order to remove the arsenic and sulphur.
Artificial pitchblende, which serves as a starting-point for the preparation of uranium compounds.
It is manufactured by heating pitchblende with lime, treating the resulting calcium uranate with dilute sulphuric acid, and adding sodium carbonate in excess.
After the discovery of the radioactive properties of uranium by Henri Becquerel in 1896, it was noticed that some minerals of uranium, such as pitchblende, were more active than the element itself, and this circumstance suggested that such minerals contained small quantities of some unknown substance or substances possessing radioactive properties in a very high degree.
And Mme Curie subjected a large amount of pitchblende to a laborious process of fractionation, with the result that in 1898 they announced the existence in it of two highly radioactive substances, polonium and radium.
Radius, ray), a metallic chemical element obtained from pitchblende, a uranium mineral, by P. and Mme.
The emission of rays like those just mentioned - as a property of some undiscovered substance, submitted pitchblende to a most careful analysis.
Becquerel in 1896 that minerals containing uranium, and particularly the mineral known as pitchblende, had the power of affecting sensitive photographic plates enclosed in a black paper envelope when the mineral was placed on the outside, as 1 See J.
Petroleum has been found near Torres Vedras; pitchblende, arsenic, anthracite and zinc are also mined.