Other Definitions
uraninite (dict)

Uraninite

olspan=2 align=center|Uraninite
olspan=2|General
ategory Mineral
a href="/encyclopedia/Chemical-formula" title="Chemical formula">Chemical formula uranum oxide, UO2
olspan=2|Identification
Colour Black or brownish
Crystal habit Massive, botryoidal, granular. Crystals uncommon.
Crystal system Isometric
Cleavage Indistinct
Fracture Conchoidal to uneven
Mohs Scale hardness 5 - 6
Luster Submetallic, greasy
Refractive index Opaque
Pleochroism None
Streak Same as colour, black or brownish
Specific gravity 7.5 - 10
Fusibility ?
Solubility Soluble in sulfuric, nitric, and hydrofluoric acids.
olspan=2|Major varieties
Pitchblende Massive
---
Uraninite is a uranium-rich mineral with a composition that is largely UO2 (uranium oxide), but which also contains UO3 and oxides of lead, thorium, and rare earths. It is most commonly known in the variety pitchblende. All uraninite minerals contain a small amount of radium as a radioactive decay product of uranium; it was in pitchblende from the Jchymov in Czechoslovakia that Marie Curie discovered radium. Uraninite also always contains small amounts of the lead isotopes, Pb-206 and Pb-207, the end products of the decay series of the uranium isotopes U-238 and U-235 respectively. Small amounts of helium are also present in uraninite as a result of alpha decay. Helium was first discovered on Earth in uraninite after previously being discovered spectroscopically in the sun's atmosphere. Uraninite is a major ore of uranium. An important occurrence of pitchblende is at Great Bear Lake in the Northwest Territories of Canada, where it is found in large quantities associated with silver. It also occurs in Germany, England, and South Africa, and in New Hampshire, Connecticut, North Carolina, Wyoming, and New Mexico in the United States.

Reference

  • Dana's Manual of Mineralogy ISBN 0471032883

See also

 

<< PreviousWord BrowserNext >>
silver spring, maryland
moulin rouge
probability density function
rave party
windmill
heuristic argument
ian dury
fairy tale
frank robinson
dord
ganja
edith stein
ross perot
axis of evil
axis powers
amen
scrabble scoring examples
abendana
rhodes piano
sywell aerodrome
hypothetical planet
three little pigs
khmer
mon language
list of movies
schist
hornblende
basalt
tectonic plate
beeswax
sacramento county, california
ruby
ruby character
action movie
heat (movie)
hindu kush
tom hanks
ghost town
lager beer riot
example scrabble tournament game
sample chess game
carmelites
list of presidents of poland
begging the question