Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A soft, silvery-white, malleable, ductile, metallic rare-earth element, obtained chiefly from monazite and bastnaesite and used in glass manufacture and with other rare earths in carbon lights for movie and television studio lighting. Atomic number 57; atomic weight 138.91; melting point 920°C; boiling point 3,464°C; specific gravity 6.145 (at 25°C); valence 2, 3. cross-reference: Periodic Table.

from The Century Dictionary.

  • noun Chemical symbol, La; atomic weight, 138. A rare metal discovered by Mosander in 1839–41, associated with didymium in the oxid of cerium, and so named from its properties having been previously concealed by those of cerium.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Chem.) A rare element of the rare earth group of the metals, of atomic number 57, allied to aluminum. It occurs in certain rare minerals, as cerite, gadolinite, orthite, etc., and was so named from the difficulty of separating it from cerium, didymium, and other rare earth elements with which it is usually associated. Atomic weight 138.9. Symbol La.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun A metallic chemical element (symbol La) with an atomic number of 57.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a white soft metallic element that tarnishes readily; occurs in rare earth minerals and is usually classified as a rare earth

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

[New Latin, from Greek lanthanein, to escape notice (from the finding of the element hidden in oxide of cerium).]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Ancient Greek λανθάνω ("escape notice"), because it had gone long undetected in mineral ores.

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Examples

  • Using material mined in past years, Molycorp produces rare-earth elements such as lanthanum, which is used in oil refining, and cerium, used in glass polishing and automotive catalytic converters.

    Molycorp, Hitachi Metals Reach Rare-Earth Deal Tess Stynes 2010

  • A metal oxide complex called lanthanum strontium manganite is ferromagnetic in large quantities.

    PhysOrg.com - latest science and technology news stories 2010

  • The cost of quotas has become exorbitant for users of lanthanum, which is vital for the catalytic converters that clean the tailpipe pollution of conventional, gasoline-powered cars.

    NYT > Home Page By KEITH BRADSHER 2010

  • It produces rare-earth elements such as lanthanum and didymium.

    Envestnet, Chesapeake Midstream IPOs Up; Molycorp's Down 2010

  • PW: From looking at the highest volume products such as lanthanum oxide, cerium oxide, cerium carbonate, dysprosium oxide, neodymium oxide etc.,

    Resource Investor - Main Content Feed Gareth Hatch 2010

  • Separators will use their quotas to ship the more valuable material first, before using quotas on lower-priced elements such as lanthanum and cerium.

    Resource Investor - Main Content Feed Gareth Hatch 2010

  • It cites China's increasing consumption and warns of a supply crunch for the metals, which include materials such as lanthanum, cerium and neodymium.

    Home/News 2010

  • Separators will use their quotas to ship the more valuable material first, before using quotas on lower-priced elements such as lanthanum and cerium.

    Resource Investor - Main Content Feed Gareth Hatch 2010

  • It cites China's increasing consumption and warns of a supply crunch for the metals, which include materials such as lanthanum, cerium and neodymium.

    Home/News 2010

  • PW: From looking at the highest volume products such as lanthanum oxide, cerium oxide, cerium carbonate, dysprosium oxide, neodymium oxide etc.,

    Resource Investor - Main Content Feed Gareth Hatch 2010

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  • La.

    December 16, 2007