(1) We found that pitchblende contains at least two radioactive materials, one of which, accompanying bismuth, has been given the name polonium, while the other, paired with barium, has been called radium.

(2) The cliff contains pitchblende veins that have been sources of dissolved uranium.

(3) Veins of pitchblende in the cliff are the source of uranium in the flat floodplain deposits at the foot of the cliff.

(4) The pitchblende is the chief industrial mineral.

(5) In 1898, Marie found anew element in the pitchblende.

(6) The radiometric age of pitchblende is 109—108 m.

(7) The distribution patterns of rare earth elements of pitchblende and surrounding rocks in three types of uranium deposits have been studied.

(8) Pitchblende is the only primary uranium mineral, which is associated with quartz, fluorite, hematite and pyrite.

(9) Marie began working with pitchblende because it contained uranium, but was cheaper to buy than pure uranium.

(10) Pitchblende is the most important industrial uranium mineral in China.

(11) Particularly part of pitchblende samples with colloidal structure features have the same physical and optical features as uraninite.

(12) Uranium mineral is pitchblende which was formed in Lower Proterozoic.

(13) Then she found that pitchblende was more radioactive than uranium by itself.

(14) The initial lead in pitchblende belongs to radioactive origin from crust.

(15) Pitchblende and chalcolite are much more radioactive than uranium itself.

(16) Curies research into the properties of two different uranium ores, pitchblende and chalcolite. led to the discovery of radium and polonium(sentencedict.com), other radioactive elements.

(17) This led her to deduce that there were other substances within pitchblende that had properties of radioactivity.

(18) The principal uranium mineral in the deposits of primary subtype is uraninite, but in reworked subtype are pitchblende and relict uraninite.

(19) The Curies undertook the arduous task of separating radium out of pitchblende ore.