Definition of bastnaesite in US English:



  • A yellow to brown mineral consisting of a fluoride and carbonate of cerium and other rare earth metals.

    • ‘A much larger, nonradioactive deposit of bastnaesite was found on adjoining land.’
    • ‘This is one of only five localities for bastnaesite within New Mexico.’
    • ‘A sample from Andakatany labeled ‘bastnaesite,’ turned out to be bastnasite- (Ce).’
    • ‘The largest single deposit of rare earths is the bastnaesite deposit at Mountain Pass, San Bernnadino County in California.’
    • ‘Bastnasite, which is sometimes spelled as bastnaesite, is one of a few rare earth carbonate minerals.’


Late 19th century: from Bastnäs, the name of a district in Västmanland, Sweden, + -ite.