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Topic: Feldspathoid

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Leucite

Mineral

Rhodonite

Feldspar

Bronzite

Apatite

List of minerals

	Nepheline syenites, etc. (Site not responding. Last check: 2007-11-05)
		Feldspathoid syenites are one of the most common and most variegated (both mineralogically and texturally) groups of alkaline rocks.
		They are broadly defined as plutonic rocks in which feldspathoid minerals account for 10-60% of all felsic minerals, and alkali feldspars are at least 10 times more abundant than Na-Ca plagioclase.
		Depending on the predominant feldspathoid mineral, this group of rocks can be further subdivided into nepheline syenites, sodalite syenites, cancrinite syenites, etc. Nepheline syenites and "mixed" sodalite-nepheline syenites are relatively common, whereas such rocks as kalsilite syenites are petrographic oddities.
	www.umanitoba.ca /geoscience/faculty/arc/nesyen.html (368 words)

	FELDSPATHOID (Site not responding. Last check: 2007-11-05)
		Feldspathoids are chemically related to the feldspars, but differ from them in crystal form and physical properties; they take the places of feldspars in igneous rocks that are undersaturated with respect to silica or that contain more alkalies and aluminum than can be accommodated in the feldspars.
		Feldspathoids may be found in the same rock with feldspars but never with quartz or in the presence of free magmatic silica.
		The feldspathoids are a group of silicate minerals which resemble feldspars but have a different structure.
	www.websters-online-dictionary.org /definition/FELDSPATHOID (354 words)

	THE FELDSPATHOID GROUP OF MINERALS
		The feldspathoids are not a typical mineral group like other mineral groups that are related by structure and chemistry.
		The aluminum to silicon ratio is nearly 1:1 in most of the feldspathoids but is closer to 1:3 in most of the feldspars.
		Similar to the zeolites, the feldspathoids have large openings in the crystal structure.
	mineral.galleries.com /minerals/silicate/feldspat.htm (220 words)

	feldspathoid - Encyclopedia.com
		Their physical and chemical properties lie between those of the feldspars and zeolites.
		The most abundant feldspathoids are nepheline and leucite.
		Feldspathoids are found chiefly in igneous and metamorphic rocks; they are used as raw materials in the production of alum, glass, and ceramics.
	www.encyclopedia.com /doc/1B1-364300.html (385 words)

	feldspathoid -- Encyclopædia Britannica
		In this role, the feldspathoids, along with minerals of the melilite group, are referred to as foids in the IUGS classification of igneous rocks.
		Feldspathoids may occur along with feldspars in igneous...
		common feldspathoid mineral, a hydrated sodium aluminosilicate (NaAlSi2O6H2O) that occurs in seams and cavities in basalt, diabase, granite, or gneiss and in extensive beds thought to have formed by precipitation from alkaline lakes.
	www.britannica.com /eb/article-9109685?tocId=9109685&query=null&ct=null (243 words)

	lithuania.ca - Feldspathoid (Site not responding. Last check: 2007-11-05)
		Sodalite is a member of the feldspathoid group...
		Additional Reading (from feldspathoid) William L. Brown (ed.), Feldspars and Feldspathoids: Structures, Properties, and Occurrences (1984).
		Feldspathoid Minerals, group of sodium and potassium alumino-silicates that appear instead of...
	www.lithuania.ca /Feldspathoid/reference/fullview/wikipedia/305429 (125 words)

	feldspathoid - Wiktionary
		A small group of igneous, plutonic, and volcanic minerals formed in magma that did not contain enough silica to satisfy all the chemical bonds.
		Feldspathoids are silica-poor variants of the feldspar group.
		This page was last modified 02:59, 24 September 2005.
	en.wiktionary.org /wiki/Feldspathoid (69 words)

	Chapter 2- Classification of Igneous ROcks
		The rock must contain at least 10% of thesum of the minerals on the corners.
		The prefix (Foid) refers to feldspathoid, a variety of generally low-silica felsic minerals like nepheline.
		It is meant to be replaced by the actual feldspathoid present, so a nepheline-bearing monzodiorite would be called a nepheline monzodiorite.
	www.union.edu /PUBLIC/GEODEPT/COURSES/petrology/shows/igneous_classification/igneous_rock_classification_slide0047.htm (80 words)

	feldspathoid -- Britannica Concise Encyclopedia - Your gateway to all Britannica has to offer!
		Any of a group of alkali aluminosilicate minerals similar to the feldspars in composition but having a lower silica-alkali ratio or containing chloride, sulfide, sulfate, or carbonate.
		The most abundant feldspathoids are nepheline and leucite.
		Feldspathoids are found chiefly in igneous and metamorphic rocks; they are used as raw materials in the production of alum, glass, and ceramics.
	concise.britannica.com /ebc/article-9364300 (93 words)

	feldspathoid
		Feldspathoids are chemically related to the feldspars, but differ from them in crystal form and physical properties; they take the places of feldspars in igneous rocks that are undersaturated with respect to silica or that contain more alkalies and aluminum than can be accommodated in the feldspars.
		Feldspathoids may be found in the same rock with feldspars but never with quartz or in the presence of free magmatic silica.
		A mineral of the feldspathoid group, including leucite, nepheline, sodalite, nosean, hauyne, lazurite, cancrinite, and melilite.
	www.webref.org /geology/f/feldspathoid.htm (195 words)

	Olympus Microscopy Resource Center: Polarized Light Microscopy Gallery - Leucite Nepheline Tephrite
		Leucite is a feldspathoid mineral that can be found only in igneous rocks.
		Leucite-tephrite is a type of igneous rock in which olivine is absent and plagioclase feldspar is present.
		When nepheline, the most common feldspathoid mineral in the world, also occurs in the rock, the basalt is described as a leucite nepheline tephrite.
	www.olympusmicro.com /galleries/polarizedlight/pages/leucitenephelinetephritesmall.html (210 words)

	feldspathoid
		Any of a group of silicate minerals resembling feldspars but containing less silica.
		Feldspathoids occur in igneous rocks that have relatively high proportions of sodium and potassium.
		Such rocks may also contain alkali feldspar, but they do not generally contain quartz because any free silica would have combined with the feldspathoid to produce more feldspar instead.
	www.screaming.net /reference/encyclopaedia/hutchinson/m0027107.html (112 words)

	Untitled Document (Site not responding. Last check: 2007-11-05)
		Sodalite is a member of the feldspathoid min eral group that is composed of minerals with essentially the same elements as the feldspars but with a smaller percentage of silica.
		Sodalite is present in the mineral aggregate lapis lazuli as a minor constituent, but it is also found in a violetish blue massive form and used as a gem and ornamental stone and, rarely, as sin gle crystals faceted for collectors (see Plate XVI).
		Sodalite is a comparatively rare mineral associated with nepheline and other feldspathoid minerals in nepheline syenites and related rocks.
	www.siamruby.com /thaigemstones_291.html (426 words)

	SODALITE (Sodium Aluminum Silicate Chloride)
		Sodalite is a member of the feldspathoid group of minerals.
		As a result or more correctly as a function of the fact, they are found in silica poor rocks containing other silica poor minerals and no quartz.
		Localities that have feldspathoids are few but some produce large quantities of sodalite.
	mineral.galleries.com /minerals/silicate/sodalite/sodalite.htm (277 words)

	Geoscience - The Earth - Shaping the Earth - Classification of igneous rocks
		Rocks that are undersaturated in silica will crystallise silica-poor minerals like feldspathoids or olivine.
		Composed of essential calcic plagioclase and pyroxene, sometimes with olivine, feldspathoids or interstitial quartz.
		Andesite: an intermediate, commonly porphyritic volcanic rock composed of plagioclase, pyroxene, hornblende and/or biotite.
	www.austmus.gov.au /geoscience/earth/igneousclass.htm (1419 words)

	Geology of Yellowcraig - glossary of terms (Site not responding. Last check: 2007-11-05)
		Amygdale: A vesicle in an igneous rock which is filled with secondary minerals.
		It is named after Essex County, Massachusetts, from where it was originally defined in 1891.
		Feldspathoid: Mineral chemically and structurally similar to feldspars, but containing less SiO
	www.geos.ed.ac.uk /undergraduate/geolsoc/field/yellowcraig/glossary.html (343 words)

	Geoscience - The Earth - Shaping the Earth - Classification of igneous rocks
		Rocks that are undersaturated in silica will crystallise silica-poor minerals like feldspathoids or olivine.
		Composed of essential calcic plagioclase and pyroxene, sometimes with olivine, feldspathoids or interstitial quartz.
		Andesite: an intermediate, commonly porphyritic volcanic rock composed of plagioclase, pyroxene, hornblende and/or biotite.
	www.amonline.net.au /geoscience/earth/igneousclass.htm (1419 words)

	feldspathoid
		Any of a group of silicate minerals resembling feldspars but containing less silica.
		Feldspathoids occur in igneous rocks that have relatively high proportions of sodium and potassium.
		Such rocks may also contain alkali feldspar, but they do not generally contain quartz because any free silica would have combined with the feldspathoid to produce more feldspar instead.
	www.tiscali.co.uk /reference/encyclopaedia/hutchinson/m0027107.html (229 words)

	IngentaConnect Marinellite, a new feldspathoid of the cancrinite-sodalite group (Site not responding. Last check: 2007-11-05)
		Marinellite, a new feldspathoid of the cancrinite-sodalite group
		O, cell parameters a = 12.880(2) Å, c = 31.761(6) Å, is a new feldspathoid belonging to the cancrinite-sodalite group.
		The crystal structure of a twinned crystal was preliminary refined in space group P31c, but space group P62c could also be possible.
	www.ingentaconnect.com /content/schweiz/ejm/2003/00000015/00000006/art00009 (356 words)

	[No title]
		The finer pieces of ore that pass through the riddle in sorting.
		A group of minerals comprising the feldspars and feldspathoids.
		feldspathoid, and (s) for silica, and applied to light-colored rocks
	www.maden.hacettepe.edu.tr /dmmrt/dmmrt430.html (489 words)

	NGDC/WDC for MGG Seafloor Series Volume 2-Core data from the ODP legs 101-129
		Note: Smear slide is from material scraped from side of barrel between Pieces 32 and 33.
		*** PHENOCRYSTS * Feldspar or feldspathoid**, 1-3 mm.
		*** PHENOCRYSTS * Feldspar or feldspathoid**, 2-4 mm.
	www.ngdc.noaa.gov /mgg/geology/odp/data/114/698A/fharvi.htm (1112 words)

	ninemsn Encarta - Search Results - Industrial Rock (Site not responding. Last check: 2007-11-05)
		Industrial Rock, genre of avant-garde rock music that uses live electronic processing effects, metal percussion, and industrial tools to achieve very...
		(from the Greek leukos, “white”), is a potassium (K)-rich feldspathoid mineral that forms tetragonal crystals.
		O], and was named after its discovery locality, Illinois, United States.
	au.encarta.msn.com /Industrial_Rock.html (72 words)

	New Page 1
		Description: a fine-grained mesocratic rock containing, in addition to plagioclase and pyroxene, nepheline or another feldspathoid.
		Location: Washinton Pass, WA Description: Granites are phaneritic, alkili-rich, silica-oversaturated rocks consisting of one or two feldspars, quartz, and a variety of mafic and opaque phases.
		Location: Westerly, RI Description: is the name used for a course-grained rock in which the amount of alkali feldspar is about the same as that of plagioclase feldspar.
	www.guilford.edu /original/academic/geology/imagelibrary/wards101-130.htm (822 words)

	Sodalite
		Sodalite is easy to distinguish from other feldspathoids when found in its usual blue form, however it is difficult to distinguish if it is not blue.
		It is the only feldspathoid that contains chlorine (and testing for chlorine is one method of distinction).
		Sodalite is soluble in a few acids, hydrochloric and nitric acid being among them, and it leaves behind a silica gel after it has dissolved.
	www.distantsunartwork.com /home/gemstones/sodalite_semi-precious_gemstone.htm (528 words)

	Additional Reading (from feldspathoid) -- Encyclopædia Britannica
		(ed.), Feldspars and Feldspathoids: Structures, Properties, and Occurrences (1984).
		More results on "Additional Reading (from feldspathoid)" when you join.
		More from Britannica on "Additional Reading (from feldspathoid)"...
	www.britannica.com /eb/article-80030?tocId=80030 (726 words)

	Encyclopædia Britannica Australia -
		The anal stage, generally the second and third years of life, is held to be significant for...
		common feldspathoid mineral, a hydrated sodium aluminosilicate (NaAlSi
		O) that occurs in seams and cavities in basalt, diabase, granite, or gneiss and in extensive beds thought to have formed by precipitation from alkaline lakes.
	www.britannica.com.au /britannica_browse/a/a48.html (1688 words)

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