Syenite definition of Syenite in the Free Online Encyclopedia.

syenite (sī`ənīt), coarse-grained igneous rock rock, aggregation of solid matter composed of one or more of the minerals forming the earth's crust. The scientific study of rocks is called petrology. Rocks are commonly divided, according to their origin, into three major classes—igneous, sedimentary, and
..... Click the link for more information. , similar in appearance and composition to granite. Unlike granite, it contains little or no quartz. The chief minerals in syenite are the feldspars, with mica, hornblende, and pyroxene. Varieties are distinguished (according to the ferromagnesian minerals contained) as augite syenite, hornblende syenite, mica syenite, and nepheline syenite. Syenites are comparatively rare rocks, being found chiefly in a few areas of the United States and Germany. They are occasionally substituted for granites as building stones.

syenite [′sī·ə‚nīt]

(petrology)

A visibly crystalline plutonic rock with granular texture composed largely of alkali feldspar, with subordinate plagioclose and mafic minerals; the intrusive equivalent of trachyte.

Syenite

a holocrystalline plutonic rock composed chiefly of orthoclase and plagioclase, with admixtures of the following ferrous minerals: hornblende, biotite, pyroxene, and, occasionally olivine. Quartz is also sometimes present.

Depending on the content of ferrous minerals, syenite is classified as hornblende syenite, micaceous syenite, quartz syenite, and so forth. Syenite is characterized chemically by a silica content of 55 to 65 percent; the alkali content determines the classification of syenite into normal and alkali types. In normal syenites plagioclases are present as oligoclase and andesite. Alkali syenites contain orthoclase and, more rarely, albite. Nephelines or other feldspathoids, such as leucite and the so-dalite group of minerals, are formed when the alkali content exceeds 12 percent and the silica content is reduced; alkali syenites thus grade into nepheline syenites or other feldspathoid syenites. Monzonites or gabbro syenites are similar to syenites. They are composed of labradorite and orthoclase with admixtures of ferrous minerals, such as pyroxene.

In the USSR, syenites are abundant in the southern Ukraine (Volyn’ Oblast), the Urals, Kazakhstan, the Caucasus, and Middle Asia, where monzonites are found. Syenites are used for the same purposes as granites.

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No references found	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. Around The World In Eighty Days by Verne, Jules View in context 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. Five Weeks in a Balloon by Verne, Jules View in context Not far from Monte Video we passed through the village of Las Pietras, so named from some large rounded masses of syenite. The Voyage of the Beagle by Darwin, Charles View in context	Sycettida Sycettidae Sychem Sychevka Sychevka Cattle Sycidales sycon syconium Sycophant Sycorax Sycosis SYDEL Sydenham's chorea Sydenham, Charles Edward Poulett Thomson, Baron Sydenham, Thomas Sydney Sydney Chapman Sydney Mines Sydney Opera House Sydney, Algernon Sydney, Sir Philip Sydney, University of Sydow, Max Von Sydykbekov, Tugelbai Syene Syenite syenodiorite syenogabbro SYGMA Sygnak SyJet disk Sykes, Lynn Ray Sykes-Picot Agreement of 1916 Syktyvkar Syktyvkar, University of Sylacauga Sylhet SYLK SYLK file Sylla, Lucius Cornelius Syllabeme syllabic syllabic compandor Syllabic Verse Literature Syllabic Versification Syllabic Writing Syllable Syllabotonic Versification syllabub syllabus Syllabus of Errors	Sydney, NSW Sydney, NSW Sydney, Sir Philip Sydney, University of Sydney-Houston System Sydneysider Sydneysider SYDO Sydow, Max von SYDP SYDR Sydrus Sydrus SYDS Sydvaranger Gruve Sydykbekov, Tugelbai SYE SYE SYEC Syed Syed Syed Ahmed Khan SYEDA syeds syeds SYEN Syena Syena Syene Syene Syenite syenites syenites syenitic syenitic syenodiorite syenogabbro SYEP SYER SYERS SYERS Front End Processor SYETP Syf SYFA SYFAB SYFAC SYFC SYFDH SYFED SYFFITF SYFH Syfilis Syfilis Syfilis SYFL SYFM SYFN SYFOC SYFP

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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.

Around The World In Eighty Days by Verne, Jules View in context

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.

Five Weeks in a Balloon by Verne, Jules View in context

Not far from Monte Video we passed through the village of Las Pietras, so named from some large rounded masses of syenite.

The Voyage of the Beagle by Darwin, Charles View in context

Syenite playV2('en/UK/df/dfsgsrdysjd3sod5hn')

Syenite