Radium seventh of a gram of radium. One kilogram of the Earth's crust contains about 900 picograms of radium, and one liter of sea water contains about 89 femtograms of radium. Radium was discovered by Marie Sklodowska-Curie and her husband Pierre Curie on 21 December 1898, in a uraninite (pitchblende) sample. While studying the mineral earlier, the Curies removed uranium from it and found that the remaining material was still radioactive. They separated out an element similar to bismuth from pitchblende in July 1898, that turned out to be polonium. They then separated out a radioactive mixture consisting mostly of two
Uranium ore province. Another example for the Breccia type is the Mount Gee area in the Mount Painter Inlier, South Australia. Uranium mineralised quartz-hematite breccia is related to Palaeoproterozoic granites with uranium contents of up to 100 ppm. Hydrothermal processes at about 300 million years ago remobilised uranium from these granites and enriched them in the quartz-hematite breccias. The breccias in the area host a low grade resource of about 31,400 t UO at 615 ppm in average. Vein deposits play a special role in the history of uranium: the term "pitchblende" ("Pechblende") originates from German vein deposits when they were mined