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Related to syenite: trachyte


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.
With Soviet help, the Zahgah mine, near Sarab 50 km east of Tabriz, will produce aluminium ore from a nepheline syenite deposit.
* MINEX[R] functional fillers and extenders are produced from nepheline syenite; a naturally occurring silica deficient, sodium-potassium aluminosilicate.
Occurrence: As a monomineralic veinlet cross-cutting poikilitic nepheline syenite. Associated minerals are: nepheline, potassium feldspar, biotite, shcherbakovite, astrophyllite, fluorapatite.
Amy Waller Turquoise Egyptian Paste Clay Body (cone 010 to cone 04) Flint 325 mesh 85 Sodium bicarbonate 6 Kentucky OM #4 ball clay 5.2 Whiting 1.9 Custer feldspar 1.9 Copper oxide 1.0 Carbon Trap Shino (cone 9 reduction) Nepheline syenite 270 mesh 40 Spodumene 30 EPK kaolin 5 Kentucky OM # 3 ball clay 17 Soda ash 8 Bentonite 2
A single yellow milarite crystal measuring 4.3 cm long and 1.1 cm wide is attached, inclining at a slight angle, to a 1 X 6 X 9-cm matrix plate of syenite. On the matrix are scattered small crystals of orthoclase, apatite, and smoky quartz, and a little fibrous actinolite ("amiant").
The Wicheeda REE Deposit, as defined by previous drill campaigns, comprises an approximately 250 x 200 metre irregular shaped intrusive plug of relatively higher-grade REE-mineralized dolomite carbonatite extending from surface to vertical depths ranging from 30 to 100 metres, below which mixed dolomite carbonate and syenite breccia rocks occur to a currently drilled maximum vertical depth of 184 metres.
DAVIS OIL SPOT 1 CONE 10/11 OXIDATION 57.40 Nepheline Syenite 19.10 Albany Slip Clay 14.40 Burnt Umber 9.10 Silica BAILEY'S OIL SPOT CONE 10/11 OXIDATION 25.52 Custer Feldspar 35.72 NC-4 (Soda Feldspar) 15.30 EPK Kaolin 5.10 Talc 5.10 Dolomite 5.10 Ferro Frit 3110 8.16 Silica 6.00 Red Iron Oxide CANDACE BLACK CONE 10/11 OXIDATION 65.00 NC-4 (Soda feldspar) 20.00 Silica 5.00 Whiting 5.00 EPK Kaolin 5.00 Dolomite 8.00 Red Iron Oxide 2.00 Cobalt Carbonate The washes I used were: LEAF WASH 1 50.00 Titanium dioxide 50.00 EPK Leaf Wash 2 33.33 Titanium dioxide 33.33 EPK 33.33 Unwashed wood ash