uraninite
IPA: jɝˈeɪnɪnaɪt
noun
- (mineralogy) Any of several brownish-black forms of uranium dioxide, UO₂, (especially pitchblende) that is the chief ore of uranium; it is isomorphous with thorianite.
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Examples of "uraninite" in Sentences
- Certain minerals, such as uraninite, cannot form under significant exposure to oxygen.
- There were two other mines that produced the same uraninite ore as the one at which Hanlon was stationed.
- This led Davidson9 to conclude that the uraninite bearing rocks are not placer riverine deposits, as is suggested by Tamzek.
- Pitchblende or uraninite is an intensely black mineral of a specific gravity of 9.5 and is found in commercial quantities in
- The principal sources of uranium and radium are the minerals carnotite (hydrous potassium-uranium vanadate) and pitchblende or uraninite (uranium oxide).
- He already knew ore -- the glossy, sub-metallic, pitchy black luster of uraninite or pitchblende; the yellows of autunite and carnotite; the variant and confusing greens of tobernite.
- He was standing there, to all appearances strictly on the job of making his charges work, when Philander came crawling up the rise into the pocket where this crew was mining the glossy, lustrous pitch-blank uraninite ore.
- On page 17 Wells notes that uraninite deposits have been found in more recent rocks, but neglects to mention to his readers that these only occur under rapid-burial conditions, whereas ancient deposits of uraninite occur in slow deposition conditions, for example in sediments laid down by rivers, so that the minerals were exposed to atmospheric gases for significant periods of time before burial.
- Tamzek asserts that the mineral uraninite, present on the early Earth, cannot form under “significant exposure to oxygen”, however a recent publication from the Nasa Astrobiology Institute stated that its P.I. had observed the, “survival of uraninite … under an oxic atmosphere” and instability of uraninite under an oxygen-poor atmosphere, which was said to be “supporting … evidence for … an oxic Archaean atmosphere.”
- Some researchers have found that the uranium conglomerates bearing uraninite have a texture and mineralogical makeup (uraninite, pyrite, molybdenite, and sulfides) one would expect if they were deposited by hydrothermal solutions, indicating that the uranium was deposited deep in the earth, far removed from the atmosphere, similar to what is observed happening in the origin of modern and more recently formed uraninite deposits9 (which obviously occurred in an oxygenic atmosphere).
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