pitchblende

pikivälke puhekieltä Naturally-occurring uranium oxide, a variety of the mineral uraninite.
2004, (w), The Earth, Folio Society 2011, p. 205:

Working in Paris in 1898, Marie and Pierre Curie processed thousands of pounds of pitchblende from the same glass-factory tailings in order to isolate two radioactive elements that had hitherto been unknown: radium and polonium.