Why was "tantrum" trending last week?


[pley-jee-uh-kleys] /ˈpleɪ dʒi əˌkleɪs/
any of the feldspar minerals varying in composition from acidic albite, NaAlSi 3 O 8 , to basic anorthite, CaAl 2 Si 2 O 8 , found in most igneous rocks: shows twinning striations on good cleavage surfaces.
Also called soda-lime feldspar.
1865-70; plagio- + -clase
Related forms
[pley-jee-uh-klas-tik] /ˌpleɪ dʒi əˈklæs tɪk/ (Show IPA),
adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
Examples from the web for plagioclase
  • plagioclase has a large number of cracks compared with quartz.
  • Anhedral plagioclase is un-twinned and mafic minerals are rare.
  • plagioclase small and sparse in the dominant mafic lavas and ejecta but abundant in thicker flows of silicic andesite.
British Dictionary definitions for plagioclase


a series of feldspar minerals consisting of a mixture of sodium and calcium aluminium silicates in triclinic crystalline form: includes albite, oligoclase, and labradorite
Derived Forms
plagioclastic (ˌpleɪdʒɪəʊˈklæstɪk) adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for plagioclase

"triclinic feldspar," 1868, from German, coined 1847 by German mineralogist Johann Friedrich August Breithaupt (1791-1873) from plagio- + Greek klasis "fracture," from stem of klan "to break" (see clastic). Related: Plagioclastic.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
plagioclase in Science
Any of a series of common feldspar minerals, consisting of differing mixtures of sodium and calcium aluminum silicates. Plagioclase is typically white, yellow, or reddish-gray, but it can also be blue to black. It occurs in igneous rocks. The minerals albite, oligoclase, andesine, labradorite, bytownite, and anorthite are all plagioclases. Chemical formula: (Na,Ca)Al(Si,Al)Si2O8.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Difficulty index for plagioclase

Most English speakers likely know this word

Word Value for plagioclase

Scrabble Words With Friends

Nearby words for plagioclase