andesite

[ an-duh-zahyt ]

/ ˈæn dəˌzaɪt /

noun

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

Nearby words

Origin of andesite

1840–50; named after Andes; see -ite¹

Related formsan·de·sit·ic

[an-duh-zit-ik] /ˌæn dəˈzɪt ɪk/, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for andesitic

Amongst them I may mention those of Bougainville Strait, which are composed of andesitic lavas of the hornblende type.
The Solomon Islands and Their Natives|H. B. (Henry Brougham) Guppy
After the cessation of the andesitic eruptions, a quiescent period of great length ensued.
The Yellowstone National Park|Hiram Martin Chittenden
These are characterized by igneous rocks of andesitic nature.
The Avifauna of Micronesia, Volume 3|Rollin H. Baker
The building fronts the west, and is constructed of an andesitic tuff of inferior quality and dark colour.
Encyclopaedia Britannica, 11th Edition, Volume 15, Slice 3|Various

It is composed of andesitic lavas of the augite type, is pierced by many fumaroles, and has a crater in the solfatara stage.
The Solomon Islands and Their Natives|H. B. (Henry Brougham) Guppy

British Dictionary definitions for andesitic

andesite

/ (ˈændɪˌzaɪt) /

noun

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

andesite

[ ăn′dĭ-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.