[ fel-sahyt ]
/ ˈfɛl saɪt /


a dense, fine-grained, igneous rock consisting typically of feldspar and quartz, both of which may appear as phenocrysts.

Origin of felsite

First recorded in 1785–95; fels(par) + -ite1

Related forms

fel·sit·ic [fel-sit-ik] /fɛlˈsɪt ɪk/, adjective
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Examples from the Web for felsite

British Dictionary definitions for felsite


felstone (ˈfɛlˌstəʊn)

/ (ˈfɛlsaɪt) /


any fine-grained igneous rock consisting essentially of quartz and feldspar

Derived Forms

felsitic (fɛlˈsɪtɪk), adjective

Word Origin for felsite

C18: fels(par) + -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 felsite


[ fĕlsīt′ ]

A fine-grained, light-colored igneous rock, consisting mainly of feldspar and quartz.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.