from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A massive variety of the mineral uraninite.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Naturally-occurring uranium oxide, a variety of the mineral uraninite.
from the GNU version of the Collaborative International Dictionary of English
- n. A pitch-black mineral consisting chiefly of the oxide of uranium; uraninite. See uraninite.
from The Century Dictionary and Cyclopedia
- n. An oxid of uranium, usually occurring in pitchy black masses, rarely in octahedrons. Also pechblend, pechblende, pechurane, uraninite.
- n. It is a black mineral found chiefly in the mines of the Erzgebirge, between Saxony and Bohemia, and until recently known simply as the chief source of oxid of uranium, used in staining glass and painting on porcelain. In it have been found many of the substances which have been observed to present the property of radioactivity.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a mineral consisting of uranium oxide and trace amounts of radium and thorium and polonium and lead and helium; uraninite in massive form is called pitchblende which is the chief uranium ore
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.
Uranium occurs chiefly as pitchblende, which is an impure oxide
They found a certain kind of pitchblende which was very active, and they analysed tons of it, concentrating always on the radiant element in it.
I wouldn't like to speculate on what that could be though I imagine if you could have a conversation now with Marie Curie about radiation she might have some thoughts about what she wished she'd known before she started work with pitchblende ores.
But the discovery in 1924 of a large pitchblende deposit in the Belgian Congo provided a more dependable radium supply and the interest in American carnotite fizzled.
Still, while the uranium at Port Radium and Shinkolobwe was found in dependable pitchblende ore, the carnotite of the American West seemed unpromising for the large amounts the Pentagon said it needed.
From several tons of pitchblende, four hundred tons of washing water, and hundreds of buckets of distilled sludge waste, they finally fished out one-tenth of a gram of the new element in 1902.
Kai and Bonnard took off north to do a depth assessment of a pitchblende strike discovered by Berru and Triv.