[ an-duh-zahyt ]
/ ˈæn dəˌzaɪt /


a dark-colored volcanic rock composed essentially of plagioclase feldspar and one or more mafic minerals, as hornblende or biotite.

Nearby words

  1. andersonville,
  2. anderssen,
  3. andes,
  4. andes lightning,
  5. andesine,
  6. andhra pradesh,
  7. andiamo,
  8. andie,
  9. andijan,
  10. andijon

Origin of andesite

1840–50; named after Andes; see -ite1

Related formsan·de·sit·ic [an-duh-zit-ik] /ˌæn dəˈzɪt ɪk/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for andesitic

British Dictionary definitions for andesitic


/ (ˈændɪˌzaɪt) /


a fine-grained tan or grey volcanic rock consisting of plagioclase feldspar, esp andesine, amphibole, and pyroxene

Word Origin for andesite

C19: from Andes + -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 andesitic


[ ăndĭ-zīt′ ]

A gray, fine-grained volcanic rock. Andesite consists mainly of sodium-rich plagioclase feldspar and one or more mafic minerals such as biotite, hornblende, or pyroxene. It often contains small, visible crystals (phenocrysts) of plagioclase.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.