Editing Uranium (section)

===Pre-discovery use===
The use of [[pitchblende]], uranium in its natural [[oxide]] form, dates back to at least the year 79 AD, when it was used in the [[Roman Empire]] to add a yellow color to [[ceramic]] glazes.<ref name="LANL" /> Yellow glass with 1% uranium oxide was found in a Roman villa on Cape [[Posillipo]] in the [[Gulf of Naples]], Italy, by R. T. Gunther of the [[University of Oxford]] in 1912.{{sfn|Emsley|2001|p=482}} Starting in the late [[Middle Ages]], pitchblende was extracted from the [[Habsburg]] silver mines in [[Jáchymov|Joachimsthal]], [[Bohemia]] (now Jáchymov in the Czech Republic) in the [[Ore Mountains]], and was used as a coloring agent in the local [[glass]]making industry.{{sfn|Emsley|2001|p=477}} In the early 19th century, the world's only known sources of uranium ore were these mines.