andesite

American  

[an-duh-zahyt] / ˈæn dəˌzaɪt /

noun

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

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andesite British  

/ ˈændɪˌzaɪt /

noun

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

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andesite Scientific  

/ ăn′dĭ-zīt′ /

1. 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.

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Other Word Forms

• andesitic
  adjective

Etymology

Origin of andesite

1840–50; named after Andes; see -ite ¹

Example Sentences

Test yourself on differentiating granite from andesite at the outdoor rock garden, meditate among CWU’s compact Japanese Garden, and watch for massive sculptures adorning CWU’s pathways.

From Seattle Times • Feb. 23, 2022

Eichelberger, J. C. Origin of andesite and dacite: evidence of mixing at Glass Mountain in California and at other circum-Pacific volcanoes.

From Nature • Dec. 12, 2017

In many places, the flowing water has worn those rocks smooth, showing how strong they are, and how seamlessly the andesite merges with the granitic rock.

From Scientific American • Jun. 4, 2017

Danny Valle, an artist from Mexico City with a long black beard, designed the sculpture as a replica of the original andesite Coatlicue, which sits in Mexico City’s Museum of Anthropology.

From The New Yorker • Sep. 23, 2014

A vast outflow of basalt and andesite swept westward from the Blue Mountains to meet a similar outflow moving eastward from the Cascades.

From The Columbia River Its History, Its Myths, Its Scenery, Its Commerce by Lyman, William Denison