• synonyms


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

Origin of felsite

First recorded in 1785–95; fels(par) + -ite1
Related formsfel·sit·ic [fel-sit-ik] /fɛlˈsɪt ɪk/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for felsite

Historical Examples of felsite

  • The stones themselves were felsite, which abounds in the locality.

    Unknown Mexico, Volume 1 (of 2)

    Carl Lumholtz

  • In the south of the island there are sills and dykes of felsite, quartz-porphyry, rhyolite, trachyte and pitchstone.

  • We found, besides, a few cores of felsite and some shapeless flakes and several fragments of large metates.

British Dictionary definitions for felsite


felstone (ˈfɛlˌstəʊn)

  1. any fine-grained igneous rock consisting essentially of quartz and feldspar
Show More
Derived Formsfelsitic (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

felsite in Science


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