**3. Use of pitchblende in glass and porcelain industries**

Klaproth had later experimented with using some yellow uranium compounds as glass colours. Some other chemists from silver metallurgical work in the Jáchymov started also with experiments using these yellow components in glassmaking industry. The Ministry for tillage of the Austrian-Hungary monarchy in Vienna recognised high interest for this new business and delegated the young chemist Adolf Patera (1819–1894) to discover a cheap technology for the production of yellow uranium colour. In the years 1851–1855, silver metallurgical work was reconstructed to factory for production of uranium yellow colours (k.k. Urangelbfabrik). Later, a new young chemist Arnošt Vysoký (1823–1872), who was named in 1866 as the director of this metallurgical and chemical works, developed some new uranium colours for the glassmaking industry (uranium orange yellow colour, uranium ammonium yellow, and high orange uranium colour) and the "black uranium colour" for the porcelain industry [3]. All these uranium colours from the Jáchymov factory were highly valued in the European market, especially in the Great Britain and France. According to high international interests for uranium colours from the Jáchymov, the original silver metallurgical work and factory for production of uranium colours in 1871 was quite reconstructed, and in 1879, this work was named as the biggest world factory for production of uranium colours. Original production of uranium colours in 1853 (84.6 kg) rose in 1886 to 12,776 kg of uranium colours. However, 10 years later, interest for uranium colours distinctly declined. After year 1896, the production of uranium colours in the Jáchymov highly declined and mining of uranium ore was almost stopped. After World War I, new competitive uranium colour factories originated in Belgium, Great Britain and Canada. The uranium colour factory in Jáchymov and factory in the Oolen, Belgium, closed in 1926 with a cartel agreement for the European market with 40% quotient for the Jáchymov factory. However, majority of glass and porcelain factories in the Czechoslovakia bayed the cheaper uranium colours from the British firms. After occupations of Jáchymov by Nazis (1938),the new Germany company (St. Joachimsthaler Bergbaugesellschaft) was established in 1939 (St. Joachimsthaler Bergbaugesellschaft), which have mined uranium ore for the German nuclear experiments. The chemical factory for producing of uranium colours and radium was closed and settled. Distinctly lower quantity of uranium colours was produced in some small factories in the German part of the Ore Mts. area (Krušné Hory/Erzgebirge), which used pitchblende mined in the Marienberg, Annaberg and Johanngeorgenstadt silver-cobalt-nickel-uranium deposits [2].
