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Webster 1913 Edition

Noun.

[1st

pitch + blende

(Min.)

A pitch-black mineral consisting chiefly of the oxide of uranium; uraninite. See

pitchblende ‎(plural pitchblendes)

(mineralogy) Naturally-occurring uranium oxide, a variety of the mineral uraninite.
- 2004, Richard Fortey, 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.

a type of uraninite

Russian: уранини́т (ru) m ‎(uraninít), ура́новая смо́лка f ‎(uránovaja smólka), смоляна́я обма́нка f ‎(smoljanája obmánka)