Definition

1. Noun:
   • A metallic chemical element belonging to the lanthanide series: A "rare-earth element" is any of a group of chemically similar metallic elements with atomic numbers from 57 (lanthanum) to 71 (lutetium) on the periodic table. Despite the name, most are relatively abundant in the Earth's crust, but they are rarely found in concentrated, economically exploitable deposits.

Usage Examples

• Noun:
  • Neodymium is a rare-earth element used to make powerful permanent magnets.
  • The mining and processing of rare-earth elements can have significant environmental impacts.
  • This new catalyst contains several rare-earth elements to improve its efficiency.

Advanced Usage

• "Rare-earth" as an attributive noun: The term "rare-earth" is frequently used adjectivally to describe materials, minerals, or industries related to these elements.
  • The country has a dominant position in the global rare-earth market.
  • Scientists are developing rare-earth-free alternatives for certain technologies.

Variants and Related Words

• Rare earth (noun phrase): Often used synonymously with "rare-earth element," or to refer to the oxides of these elements.
  • The deposit is rich in rare earths.
• Lanthanide (noun): The technical chemical series name for the set of elements from lanthanum (57) to lutetium (71). Scandium and yttrium are often included in commercial/geological discussions of rare earths due to similar properties, though they are not lanthanides.
  • The lanthanides are known for their magnetic and luminescent properties.
• REE (initialism): A common abbreviation for "rare-earth element(s)."
  • The report analyzed the concentration of REEs in the sample.

Synonyms

• Lanthanoid: A synonym for lanthanide, often used in scientific contexts.
• Inner transition metal: A broader category of metallic elements on the periodic table that includes the lanthanide and actinide series.

Related Phrases and Terms

• Rare-earth magnet: A strong permanent magnet made from alloys of rare-earth elements.
  • The motor uses rare-earth magnets for high power density.
• Rare-earth mineral: A mineral that is a significant source of one or more rare-earth elements.
  • Bastnäsite and monazite are important rare-earth minerals.

Noun

1. any element of the lanthanide series (atomic numbers 57 through 71)