Definition of "praseodymium" []

• A soft, silvery, malleable, ductile rare-earth element that develops a characteristic green tarnish in air. It occurs naturally with other rare earths in monazite and is used to color glass and ceramics yellow, as a core material for carbon arcs, and in metallic alloys. Atomic number 59; atomic weight 140.908; melting point 935°C; boiling point 3,127°C; specific gravity 6.8; valence 3, 4. See Table at element. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "To slow down the light, the researchers used a silicate crystal doped with a rare-earth element called praseodymium ."
• "I doubt if your people would take kindly to ... say ... catastrophic inflation when we released several tons of the praseodymium which is your standard, followed by depression and unemployment when a number of key corporations retired from business. '"
• "China supplies at least 95% of the world's rare earths -- 17 chemical elements with hard-to-pronounce names such as praseodymium and yttrium -- essential for a wide range of high-tech devices and green technologies."