[ dahy-uh-rahyt ]
/ ˈdaɪ əˌraɪt /


a granular igneous rock consisting essentially of plagioclase feldspar and hornblende.

Origin of diorite

1820–30; < French < Greek dior(ízein) to distinguish (see di-3, horizon) + French -ite -ite1
Related formsdi·o·rit·ic [dahy-uh-rit-ik] /ˌdaɪ əˈrɪt ɪk/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for diorite

British Dictionary definitions for diorite


/ (ˈdaɪəˌraɪt) /


a dark coarse-grained igneous plutonic rock consisting of plagioclase feldspar and ferromagnesian minerals such as hornblende
Derived Formsdioritic (ˌdaɪəˈrɪtɪk), adjective

Word Origin for diorite

C19: from French, from Greek diorizein to distinguish (from dia- apart + horizein to define) + -ite 1
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

Science definitions for diorite


[ dīə-rīt′ ]

A gray, coarse-grained plutonic rock. Diorite consists mainly of sodium-rich plagioclase and one or more mafic minerals such as biotite, hornblende, or pyroxene. It is the coarse-grained equivalent of andesite.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.