syenite

American  

[sahy-uh-nahyt] / ˈsaɪ əˌnaɪt /

noun

1. a granular igneous rock consisting chiefly of orthoclase and oligoclase with hornblende, biotite, or augite.

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syenite British  

/ ˌsaɪəˈnɪtɪk, ˈsaɪəˌnaɪt /

noun

1. a light-coloured coarse-grained plutonic igneous rock consisting of feldspars with hornblende or biotite

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syenite Scientific  

/ sī′ə-nīt′ /

1. A light-colored, coarse-grained igneous rock consisting primarily of alkali feldspar together with some mafic minerals, especially hornblende. Unlike most igneous rocks, syenite has little or no quartz. It is believed to form from the cooling of magma that forms at very high temperatures and at great depths. It is the coarse-grained equivalent of trachyte.

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Other Word Forms

• syenitic adjective

Etymology

Origin of syenite

First recorded in 1790–1800; from Latin syēnītēs (lapis) “(stone) of Syene” (the ancient name of Aswan, an Egyptian city on the Nile), from Greek syēnī́tēs (líthos); see -ite ¹

Example Sentences

Rocks labeled as ‘granite’ in laymen applications can be several other rocks, including syenite, tonalite, and monzonite.

From Textbooks • Jan. 1, 2017

Most of these tracks end behind large boulders of dolostone or syenite, some however start and end without an apparent object nearby.

From Scientific American • Jul. 22, 2013

The hills, which are mainly composed of granite, serpentine and syenite, rise in irregular masses to considerable heights, the loftiest point, Victoria Peak, reaching an altitude of 1825 ft.

From Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 6 "Home, Daniel" to "Hortensius, Quintus" by Various

The hills are composed principally of granite and syenite, and have little vegetation.

From Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 4 "Aram, Eugene" to "Arcueil" by Various

The most remarkable boulder, for instance, of a weight of at least an hundred tons, was distinctly recognisable as identical in every respect with the granitic syenite of Schooley's mountain, distant at least forty miles.

From The American Quarterly Review, No. 17, March 1831 by Walsh, Robert