uraninite

American  

[yoo-ran-uh-nahyt, -rey-nuh-] / yʊˈræn əˌnaɪt, -ˈreɪ nə- /

noun

1. a mineral, probably originally uranium dioxide, UO 2 , but altered by radioactive decay, and usually containing uranium trioxide, lead, radium, and helium, occurring in several varieties, including pitchblende: the most important ore of uranium.

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uraninite British  

/ jʊˈrænɪˌnaɪt /

noun

1. a blackish heavy radioactive mineral consisting of uranium oxide in cubic crystalline form together with radium, lead, helium, etc: occurs in coarse granite. Formula: UO 2

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Etymology

Origin of uraninite

First recorded in 1875–80; uran(ium) + -in ² + -ite ¹

Example Sentences

Uranium is soluble in oxidizing groundwater environments and precipitates as uraninite when reducing conditions are encountered.

From Textbooks • Jan. 1, 2017

With many such "ifs" Professor Lane estimates the present age of uraninite as 1,070,000,000 years, of pitchblende as 1,300,000,000 years.*

From Time Magazine Archive

In 1896 Ramsay at last succeeded in separating helium, recognized by the same yellow line in its spectrum, in minute quantities from the mineral uraninite.

From The New Heavens by Hale, George Ellery

On the occurrence of nitrogen in uraninite, and on the composition of uraninite in general. 38pp.

From United States Government Publications, v. 8 Jan-Jun 1892 A Monthly Catalog by Compiled

H. Miers drew Ramsay’s attention to the work of W. F. Hillebrand, who had noticed, in examining the mineral uraninite, that an inert gas was evolved when the mineral was decomposed with acid.

From Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 2 "Hearing" to "Helmond" by Various