Fourth, about four litres of helium were prepared from fergusonite; and this gas was fractionally diffused during about three months, in the hope of obtaining heavier fractions, which might contain the looked-for gases; for they would certainly betray themselves by their spectra, if present.    From Wordnik.com.  [Sir William Ramsay - Nobel Lecture] Reference

It is important to realize that the tantalum, niobium and zirconium production does not involve significant extra costs as they occur in the same mineral phases that contain the heavy rare earths (zircon and fergusonite).    From Wordnik.com.  [Latest News - Yahoo!7 News] Reference

By contrast, Dotson Ridge is characterized by steeply dipping pegmatitic and aplitic dikes variably mineralized with REE minerals including kainosite, xenotime, allanite, bastnaesite, thalenite, synchisite, and fergusonite.    From Wordnik.com.  [Marketwire - Breaking News Releases] Reference

The minerals observed in these three showings are fergusonite, chevkinite, gadolinite, pyrochlore, zircon, monazite, allanite and ferrocolombite.    From Wordnik.com.  [Marketwire - Breaking News Releases] Reference

To date, a wide variety of REE-bearing minerals have been identified, including apatite, iimoriite, kainosite, gadolinite, allanite, bastnaesite, parisite, brannerite, thalenite, xenotime, fergusonite, synchysite (Y), and monazite.    From Wordnik.com.  [Marketwire - Breaking News Releases]