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An igneous rock composed primarily of alkali feldspar together with other minerals, such as hornblende.

[Latin Syēnītēs (lapis), (stone) of Syene, from Syēnē, Syene, an ancient city of southern Egypt, from Greek Suēnē.]

sy′e·nit′ic (-nĭt′ĭk) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Geological Science) a light-coloured coarse-grained plutonic igneous rock consisting of feldspars with hornblende or biotite
[C18: from French syénite, from Latin syēnītēs lapis stone from Syene (Aswan), where it was originally quarried]
syenitic adj
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈsaɪ əˌnaɪt)

a granular igneous rock consisting chiefly of orthoclase and oligoclase.
[1790–1800; < Latin syēnītēs (lapis) (stone) of Syene]
sy`e•nit′ic (-ˈnɪt ɪk) adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
References in classic literature ?
Copses of dates and dwarf-palms succeeded the dense forests; then vast, dry plains, dotted with scanty shrubs, and sown with great blocks of syenite. All this portion of Bundelcund, which is little frequented by travellers, is inhabited by a fanatical population, hardened in the most horrible practices of the Hindoo faith.
It was then passing over Mabunguru, a stony country, strewn with blocks of syenite of a fine polish, and knobbed with huge bowlders and angular ridges of rock; conic masses, like the rocks of Karnak, studded the soil like so many Druidic dolmens; the bones of buffaloes and elephants whitened it here and there; but few trees could be seen, excepting in the east, where there were dense woods, among which a few villages lay half concealed.
Not far from Monte Video we passed through the village of Las Pietras, so named from some large rounded masses of syenite. Its appearance was rather pretty.
Geology and petrology of felspathoidal syenites and associated rocks of Koga area, Chamla valley, Swat, West Pakistan.
The bedrock at Zagi Mountain is part of the Warsak igneous complex (Ahmand et al., 1969; Kempe, 1973; Khan, 1990), which is itself part of the Peshawar plain alkaline igneous province, a group of alkaline granites, syenites and nepheline syenites which crop out around the margins of the Peshawar basin.
Geology and petrology of the feldspathoidal syenites and pegmatites of the Koga area, Chamla valley, Swat, West Pakistan.
(1992) The regional geology of the Pocos de Caldas alkaline complex: mineralogy e geochemistry of selected nepheline syenites e phonolites.
They are LREE-enriched peralkalic syenites and alkalic syenitoids with potassium feldspar, plagioclase, quartz, biotite and aegirine-augite as their common minerals.
The majority of zeolite occurrences described here are in rocks within or adjacent to the Central Metasedimentary Belt (CMB) of the Grenville Province, probably an ancient island arc, composed largely of Precambrian marbles, gneisses, amphibolites, granites, syenites, etc., formed by tectonic and plutonic mountain-building events (Grenville orogeny) at ~950-1080 Ma, during which amphibolite-to-granulite facies conditions were attained.
Most of the rocks in the study area include syenites, feldspathoidal syenites, fenites, carbonates and associated rocks(Siddique, 1965, 1967).
Quartz-apatite-magnetite rocks, carbonatite, and syenites are some other significant rocks reported from Beldih region [9-12].
For more than a century, at a myriad of collecting sites in the small stream drainages which decline to the Rhone in Tujetsch, crystallized clefts in gneisses, granodiorites, syenites and aplites have yielded minerals of the Fundortgruppe 3 paragenesis of Parker (1973).