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	Serpentine - Wikipedia, the free encyclopedia
		The more attractive and durable varieties (all of antigorite) are termed "noble" or "precious" serpentine and are used extensively as gems and in ornamental carvings.
		Antigorite is named after its type locality, the Valle di Antigorio in Italy.
		Two translucent varieties of antigorite, bowenite and williamsite, are prized by artisans and collectors for their ornamental value; these are the "precious serpentines".
	en.wikipedia.org /wiki/Serpentine (925 words)

	iqexpand.com (Site not responding. Last check: 2007-10-09)
		Antigorite Antigorite is a silicate of composition (Mg,Fe) 3 Si 2 O 5 (OH) 4.
		Antigorite : pale green, massive / compact, with waxy or greasy luster Antigorite {(Mg,Fe) 3 Si 2 O 5 (OH) 4 } is a mineral of the serpentine group.
		Antigorite Data Antigorite, lizardite and chrysotile are the three mineral polymorphs that constitute andquot;serpentine.andquot; Antigorite and lizardite are the soft green platy minerals in serpentine, whil e...
	antigorite.iqexpand.com /index.php?title=Antigorite&action=edit (306 words)

	[No title]
		Antigorite 15 Serpentine Essentially in shear zones and tensional filaments and veinlets.
		Growing at the expense of antigorite in or near deformed chrysotile veinlets.
		In shear planes, antigorite is parallel to the direction of the shear zone.
	www.ngdc.noaa.gov /mgg/geology/odp/data/109/670A/hrthin.txt (527 words)

	Antigorite: High-pressure stability in the system MgO-SiO2-H2O (MSH) (Site not responding. Last check: 2007-10-09)
		The breakdown reactions of antigorite (1) forming talc + forsterite + water at low pressures and (2) forming forsterite + clinoenstatite + water at high pressures were determined in reversed equilibrium experiments.
		On the basis of these new data on the stability of antigorite, earlier conclusions about dehydration depths in subducted serpentine-bearing oceanic lithosphere have to be reconsidered.
		The maximum pressure stability of antigorite according to reaction (16) extends between 44 and 55 kbar, that is between about 130 and 160 km, as opposed to about 75 kbar (220 km) following Ulmer and Trommsdorff (1995a).
	www.gfz-potsdam.de /pb4/pg1/people/wunderabstracts/wunder-abs5.html (408 words)

	Serpentine at Martin's Jewelry - Information on serpentine gemstones including jewelry, formation, properties, history ...
		It crystallizes in the monoclinic system and occurs in two distinct forms: antigorite, a massive variety, and chrysotile, a fibrous variety.
		Both varieties are colored light and dark green, which in massive formations of antigorite produce a beautiful, variegated coloring.
		Antigorite, often used as an ornamental stone, sometimes occurs as a collateral mineral in verd antique marble.
	www.martins-jewelers.com /gemstones/serpentine.shtml (223 words)

	[No title]
		Antigorite is a subcategory of serpentine but unlike chrysotile or lizardite, antigorite lacks naturally occurring fibre, though it shares similar chemical and physical characteristics.
		Hedman's new management concluded that if its antigorite could be fiberized, and based on its melt point being measurably higher than basalt, the result could be an enviable product that would equate with basalt/ceramic composites at a substantially lower cost, as well as offering its own specialized uses and applications.
		The ARC became interested in Hedman's antigorite because (a) it is the only known antigorite deposit in North America, and (b) it is the only known serpentine deposit that has been conclusively shown to be free of asbestos-like contaminants.
	www.cdnx.com /data/lcdb/DOCP/NOV2004/T_YJ01!.DOC (2633 words)

	Discussion
		Antigorite is unstable at high temperatures, therefore dehydration embrittlement is unlikely to occur in the mantle wedge overlying the subducting slab.
		In the Nazca plate seismic activity above 160 km depth is low suggesting that dehydration embrittlement in antigorite may be only of minor importance as the causative mechanism in that depth range.
		Water carried to greater depths may be contained beyond the stability field of antigorite in phase A [Wunder and Schreyer, 1997].
	www.agu.org /pubs/toc/gl/gl/gl0023/2000GL011881/node3.html (750 words)

	Rocks & Minerals: Alphine Minerals (Site not responding. Last check: 2007-10-09)
		Mineral occurrences in the ultrabasic Geisspfad complex (mainly antigorite serpentinite): The ultrabasic Geisspfad complex, comprising mainly an antigorite-serpentinite, was derived from an originally lherzolitic rock (Keusen 1972) that was transformed into its present state by various geological processes, mainly as a result of Alpine metamorphism.
		Elements, sulfides Silicates native copper antigorite(*) chalcocite chlorite minerals cubanite diopside djurleite epidote galena forsterite pentlandite garnets: andradite, and var.
		Presumably, the serpentine polymorph antigorite (described as a new species by Schweizer 1840) originates from the Geisspfad complex: The pebbles found in the Antigorio Valley, which served as type material, undoubtedly were derived from the Geisspfad complex.
	www.findarticles.com /p/articles/mi_m0GDX/is_1998_Jan/ai_53285929/pg_6 (1282 words)

	thesis (Site not responding. Last check: 2007-10-09)
		The dehydration of antigorite, a serpentine mineral that is widely suspected to be a major water source for arc volcanism, is the focus of the present experimental study.
		When antigorite is subjected to pressures and temperatures exceeding those of its stability field, it decomposes into water and the minerals forsterite and enstatite.
		In this study, a series of experiments was conducted to determine the equilibrium temperature for this reaction at a pressure of 2GPa, which is equivalent to 65km of depth beneath the Earth’s surface.
	people.umass.edu /aehmann/thesis.html (300 words)

	Serpentine Group (Mg6Si4O10(OH)8)
		It is fine grained, composed mostly of antigorite (serpentine) and talc.
		Within the serpentine group, chrysotile and lizardite are true polymorphs, but antigorite has different composition, although the chemical formula is the exact same.
		He studies the distribution of potentially hazardous material in the bedrock, such as chrysotile, tremolite, lizardite, antigorite, and other serpentine and amphibolite minerals.
	www.und.nodak.edu /instruct/mineral/geol318/webpage/brandvik (2242 words)

	IngentaConnect Antigorite: Pressure and temperature dependence of polysomatism a... (Site not responding. Last check: 2007-10-09)
		The change in the crystal structure of antigorite is combined with a gradual partial dehydration process and loss of MgO.
		For the formulation of reactions that include antigorite, the P,T-dependence of the chemical composition of antigorite has to be considered.
		The successive partial dehydration of antigorite during ongoing subduction of serpentine-bearing oceanic lithosphere probably influences its rheological properties.
	api.ingentaconnect.com /content/schweiz/ejm/2001/00000013/00000003/art00006 (202 words)

	Mineral description : Serpentine (Site not responding. Last check: 2007-10-09)
		Antigorite : As thick lamellar masses, fibrous or massive.
		Serpentine is a common name for the minerals antigorite, lizardite and chrysotile.
		If you have some questions, suggestions or comments you are welcome to write me a line or two.
	www.geology.neab.net /minerals/serpenti.htm (167 words)

	GemRocks: Serpentine
		, these two are varieties of antigorite -- so these names are not recognized by professional mineralogists.
		Antigorite - a recognized species of the serpentine-kaolinite series.
		Bowenite (precious serpentine) - a translucent, cream to blue-green, typically fine-grained massive variety of antigorite much of which has a greater hardness and higher specific gravity than so-to-speak typical serpentine -- an example is the material from the Conklin Quarry, near Limerock, Cumberlain Township, Rhode Island.
	www.cst.cmich.edu /users/dietr1rv/serpentine.htm (1762 words)

	serpentine.htm (Site not responding. Last check: 2007-10-09)
		Description: Serpentine is a family of polymorphs that include the flaky to platy antigorite, massive lizardite and fibrous clinochrysotile, orthochrysotile and parachrysotile.
		RUSK COUNTY: Antigorite occurs in metamorphosed iron formation, mafic tuffs and diabase dikes in the Eisenbrey massive sulfide deposit north of Ladysmith.
		It is often as platy antigorite, intergrown with talc.
	www.uwrf.edu /~william.s.cordua/serpentine.htm (549 words)

	Zeal.com - United States - New - Library - Sciences - Earth & Environment - Geology - Mineralogy & Petrology - ... (Site not responding. Last check: 2007-10-09)
		Review facts for a mineral known as antigorite, including the location where the mineral is found, the crystal system, and the formula.
		Gives a sorted list of the mineralogical properties of antigorite, the year the mineral was discovered, and the country of origin.
		Find the relationship of antigorite to other species, the mineral classification, optical data, the crystallography, and the physical and chemical properties.
	www.zeal.com /category/preview.jhtml?cid=10179867 (277 words)

	IngentaConnect Insights into the antigorite structure from Mossbauer and FTIR sp... (Site not responding. Last check: 2007-10-09)
		Pure, selected samples of antigorite (#7 and #18, from Elba Island veins, Italy, with superperiodicities of 38 and 49 Å, respectively) have been analyzed by Mössbauer and infrared spectroscopies.
		The infrared spectra of antigorites #7 and #18 are similar, with minor shifts in peak positions.
		We conclude that antigorite and lizardite share common features (similar iron coordination and disordered distribution within the magnesium octahedra), but differ in the oxidation state (more reduced antigorite), in the tetrahedral sheet size (basal Si-O bond shrinked by 0.009 Å in antigorite) and in the interlayer connections mechanism (absence of hydrogen bond in antigorite).
	api.ingentaconnect.com /content/schweiz/ejm/2002/00000014/00000001/art00010 (353 words)

	Antigorite Gallery (Site not responding. Last check: 2007-10-09)
		Large specimen of translucent, green antigorite serpentine with the face polished to reveal the inner color.
		Long, lath-like crystals of green antigorite with lighter, brownish fibers on the surface where the antigorite has altered to asbestos.
		Specimens from this occurance even fall somewhat short of a true Antigorite identity, but is closest to this family member of the Sepentine group.
	www.mindat.org /gallery.php?min=260 (395 words)

	Read about Serpentine at WorldVillage Encyclopedia. Research Serpentine and learn about Serpentine here! (Site not responding. Last check: 2007-10-09)
		The Maori of New Zealand once carved beautiful objects from local serpentine, which they called tangiwai, meaning "tears." Material quarried in
		It has a hardness of 3.5–4 and its lustre is greasy.
		Antigorite is named after its type locality, the
	encyclopedia.worldvillage.com /s/b/Serpentine (781 words)

	Structural geology in italian Alps. The structural, geophysical and petrografic study. Relationships between ...
		It was observed that the Sx+1 schistosity is the axial plane schistosity developed during the deformations F1 and F2 recognized at a regional scale
		The serpentinites shows structures developed during the uplift, in particular the Sx+1 schistosity: it is considered related to the F1 and F2 deformation.
		The Sx+1 schistosity is accompanied by the developement of antigorite and chlorite.
	italiangeology.tripod.com /lostudioingl.htm (938 words)

	The serpentine mineral group
		Antigorite, Clinochrysotile, Cronstedtite, Fraipontite, and Nepouite all crystallize in the
		Antigorite - An individual mineral in the Serpentine group.
		Its former use, which has been outlawed in most areas, was as an insulator, but has been banned because of its notorious nature of causing cancer and other long term illnesses.
	www.minerals.net /mineral/silicate/phyllo/serpenti/serpenti.htm (846 words)

	USGS Spectroscopy Lab - Clark et. al. 2003 Spectral Library splib05a (Site not responding. Last check: 2007-10-09)
		Antigorite collected from Red Hill 6.5 km west of Chinese Camp, California, USA
		Antigorite sample is pale green massive antigorite with picrolitic partings also made of antigorite.
		X-ray diffraction indicates that the sample is composed of antigorite (a non-fibrous serpentine mineral in the same mineral group as chrysotile asbestos).
	speclab.cr.usgs.gov /PAPERS/paper.splib05a/review.6.2003.old/DESCRIPT/V/antigorite_grass20.html (85 words)

	Research Results For Antigorite (Site not responding. Last check: 2007-10-09)
		Antigorite is an iron-bearing secondary mineral found in serpentine.
		Antigorite is a hydrous silicate of magnesium and iron and belongs to the kaolinte-serpentine group of minerals.
		It has a green or yellowish-green colour and has a resilient structure making it suitable for carving and polishing, often being sold as a cheap artificial jade.
	www.probertencyclopaedia.com /cgi-bin/res.pl?keyword=Antigorite&offset=0 (98 words)

	antigorite -- Encyclopædia Britannica
		"antigorite." Encyclopædia Britannica from Encyclopædia Britannica Premium Service.
		Serpentine generally occurs in three polymorphs: chrysotile (q.v.), a fibrous variety used as asbestos; antigorite, a variety occurring in either corrugated plates or fibres; and lizardite, a very fine-grained, platy variety.
		Minerals of this groups are 1:1 layer silicates.
	www.britannica.com /eb/article-9007830?tocId=9007830 (196 words)

	Serpentinitic soils (Site not responding. Last check: 2007-10-09)
		Serpentinite is a rock consisting primarily of serpentine minerals, e.g., chrysotile, lizardite, and antigorite, with the generalized chemical formula [Mg Si
		Lizardite and antigorite have platy morphology, whereas chrysotile has tubular or fibrous morphology.
		Fibrous chrysotile is a mineral of the asbestos group (1) and is known to cause serious human-health problems (2-3).
	213.212.74.236 /sdek/65897250-16641400/abstract~db=enc~content=a713571948 (203 words)

	Gems in Brief, S-Z (Site not responding. Last check: 2007-10-09)
		Serpentine is an aggregate of two minerals, antigorite and chrysotile.
		Conversely, antigorite has a monoclinic crystalline structure that creates a micaceous habit.
		Therefore, antigorite has perfect cleavage in one direction and possesses a conchoidal fracture.
	www.emporia.edu /earthsci/amber/go340/gb4.htm (2393 words)

	IngentaConnect Serpentinite Subduction: Implications for Fluid Processes and Tra... (Site not responding. Last check: 2007-10-09)
		The oxygen isotope compositions of the high-pressure antigorite serpentinites largely mirror those of the pre-subduction protoliths.
		The antigorite breakdown reaction appears to produce a mobile fluid that can play a role in the metasomatism of sub-arc mantle.
		Serpentinized oceanic mantle thus represents a valuable candidate reservoir for fluids and incompatible elements: consequently, its role in the overall element cycle in subduction settings should be re-evaluated.
	www.ingentaconnect.com /content/bell/igr/2004/00000046/00000007/art00002 (409 words)

	The stability of antigorite in the systems MgO-SiO2-H2O (MSH) and MgO-Al2O3-SiO2-H2O (MASH): The effects of Al3+ ...
		The stability of antigorite in the systems MgO-SiO2-H2O (MSH) and MgO-Al2O3-SiO2-H2O (MASH): The effects of Al3+ substitution on high-pressure stability -- Bromiley and Pawley 88 (1): 99 -- American Mineralogist
		antigorite = forsterite + clinoenstatite + chlorite + water
		previous studies on the stability of antigorite at high pressure.
	ammin.geoscienceworld.org /cgi/content/abstract/88/1/99 (427 words)

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