dacite

American  

[day-sahyt] / ˈdeɪˌsaɪt /

noun

plural

dacites

1. Geology. a gray volcanic rock similar to andesite but bearing quartz as a distinct characteristic.

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dacite Scientific  

/ dā′sīt′ /

1. A fine-grained light gray volcanic rock consisting primarily of quartz, plagioclase feldspar, and potassium feldspar, and also containing biotite, hornblende, or pyroxene. It is the fine-grained equivalent of granodiorite.

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Other Word Forms

• dacitic adjective

Example Sentences

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

I. Phase equilibria and pre-eruption P-T-fO2-fH2O conditions of the dacite magma.

From Nature • Dec. 12, 2017

Those gasses ripped and plucked existing rock from the debris avalanche and the ground, mixed that rock with the hot young dacite from the cryptodome, and hurled the whole mass along at incredible speeds.

From Scientific American • Dec. 13, 2012

I went to school at the foot of a mountain made of dacite, the same kind of magma that blew Mount St. Helens apart.

From Scientific American • Dec. 6, 2012

All this gossan and porphyry, and that copper stain up there–and just look at that dacite cap!”

From Silver and Gold A Story of Luck and Love in a Western Mining Camp by Coolidge, Dane