Definition of "pitchblende" [pitch•blende]

• A massive variety of the mineral uraninite. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Between 1898 and 1899, the Curies received 1.1 tons of pitchblende from the Austrians."
• "In their attempt to separate radium from bismuth, both contained in pitchblende, Marie and Pierre found that by crystallizing the chloride of radioactive barium from a solution, they obtained crystals that were more radioactive and richer in radium than the chloride which remained resolved."
• "In a waste ore called pitchblende, a black sludge that came from the peaty forests of Joachimsthal in what is now the Czech Republic, the Curies found the first signal of a new element—an element many times more radioactive than uranium."