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Topic: Pyrrhotite

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	Pyrrhotite from Central Wales (Site not responding. Last check: 2007-10-27)
		Pyrrhotite decay is often quite impressive - the texture reminds me of the foliage hanging over a mangrove swamp.
		The only other pyrrhotite locality in Central Wales is Dylife mine, in the orefield's NE sector, where a few samples have been found over the years.
		Incidentally, pyrrhotite is a major and widespread sulphide in the pre-Acadian metalliferous vein suites of the Dolgellau Gold-belt and the Snowdon Caldera, both to the north of Central Wales.
	www.geologywales.co.uk /pyrrhotite.htm (125 words)

	PYRRHOTITE - LoveToKnow Article on PYRRHOTITE (Site not responding. Last check: 2007-10-27)
		The mineral is magnetic, sometimes with polarity, and it is therefore often called magnetic pyrites Pyrrhotite occurs in metalliferous veins, and as grains and plates disseminated through various rocks.
		Crystallized specimens are from the metalliferous veins at Morro Velho in Brazil, Kongsberg in Norway, and Andreasberg in the Harz.
		Crystals of pyrrhotite have also been observed in meteoric stones; but iron sulphide appears more commonly in meteorites, especially in meteoric irons, as troilite (FeS), which, if really distinct from pyrrhotite, has not been met with in terrestrial rocks.
	83.1911encyclopedia.org /P/PY/PYRRHOTITE.htm (257 words)

	pyrrhotite.htm (Site not responding. Last check: 2007-10-27)
		R.16E.) The pyrrhotite is bronzy, iridescent and strongly magnetic.
		RUSK COUNTY: Pyrrhotite is a minor component of the massive sulfide ore at the Flambeau Mine, near Ladysmith.
		Pyrrhotite is a major component of the Eisenbrey massive sulfide deposit north of Ladysmith (NW sec.
	www.uwrf.edu /~wc01/pyrrhotite.htm (474 words)

	Pyrrhotite - Wikipedia, the free encyclopedia
		Also called magnetic pyrite because the color is similar to pyrite and it is weakly magnetic, the magnetism increases as the iron content decreases.
		When pyrrhotite is high in iron and the formula is closer to true FeS the structure is hexagonal.
		Pyrrhotite is a rather common trace constituent of igneous rocks.
	en.wikipedia.org /wiki/Pyrrhotite (182 words)

	[No title] (Site not responding. Last check: 2007-10-27)
		Amphibole grp., apatite grp., augite, biotite, calcite, chalcopyrite, dolomite, magnetite, olivine, phlogopite, pyrite, pyrochlore, pyrrhotite, riebeckite, salite, titanite, zircon.
		Aegirine, amphibole grp., analcime, apatite grp., barite, biotite, calcite, cancrinite, chalcopyrite, chlorite, grp., diopsiide, dolomite, fluorite, garnet grp., hematite, kaersutite, magnetite, muscovite (sericite), nepheline, olivine, perthite, pyrite, pyroxene grp., pyrrhotite.
		Apatite grp., augite, biotite, britholite-(Ce), calcite, diopside, dolomite, hauyne, latrappite, magnetite, melilite, monticellite, nepheline, niocalite, periclase, perovskite, pyrite, pyrochlore, pyroxene grp., pyrrhotite, richterite, wollastonite.
	www.koeln.netsurf.de /~w.steffens/can.htm (2311 words)

	Pyrrhotite
		Pyrrhotite, in grains, rounded crystals, and irregular masses, is common in the white limestone in quarries near Franklin.
		No individual crystals of pyrrhotite were found with plain faces, though many of them presented two broader surfaces that suggested original basal planes of crystals, now rounded and deeply etched by resorption.
		Masses of pyrrhotite were found in immediate contact was tourmaline and titanite, evidently later and molded against the surface of those minerals.
	simplethinking.com /palache/pyrrhotite.stm (153 words)

	Rocks & Minerals: Pyrrhotite: Santa Eulalia, Chihuahua, Mexico - Connoisseur's Choice (Site not responding. Last check: 2007-10-27)
		Pyrrhotite was found in crystals to at least 2.5 cm across in the Tilly Foster iron mine, Putnam County, New York; in tabular pseudohexagonal crystals to 2 cm in the amazonite breccia at the Rutherford No. 2 pegmatite, Amelia County, Virginia; and in crystals with andalusite at Standish, Maine.
		Pyrrhotite is widely distributed in the ores of California (Murdoch and Webb 1966) but is reported as idiomorphic crystals at only a few localities, such as an occurrence on Mount Tamalpais in Marin County.
		Pyrrhotite crystals to 2 cm are reported also from mines at Naica, Chihuahua, and crystals to 4 cm across have been found associated with pyrite, boulangerite, and jamesonite at Noche Buena, Zacatecas (Panczner 1987).
	www.findarticles.com /p/articles/mi_m0GDX/is_4_78/ai_104522726 (1216 words)

	PYRRHOTITE Chapter 21. Sulfides, arsenides, antimonides, and sulfosalts
		Pyrrhotite was described from the Franklin Marble by Palache (1935); the date of original recognition is obscure.
		The preponderance of local pyrrhotite is found in the Franklin Marble, associated always with calcite, commonly with graphite, fluorite, pargasite, pyrite, arsenopyrite, and scapolite, and occasionally with chondrodite, titanite, and uvite (Palache, 1935).
		Pyrrhotite also occurs as 3 mm blebs in magnetite inclusions in the fl-willemite occurrence at Franklin.
	simplethinking.com /dunn/ch21/pyrrhotite.stm (233 words)

	SAMPLE DESCRIPTION (Site not responding. Last check: 2007-10-27)
		The quartz-lined fractures are infilled with pyrrhotite (80%-90%), chalcopyrite (8%-15%), and magnetite (2%-5%).
		Pyrrhotite is present as distinctive 0.1- to 0.25-mm crystals with Fe silicate alteration along the cleavage traces.
		Pyrrhotite stringers found throughout the pyrite have apertures of <0.1 mm and comprise ~15% of the opaque phases.
	www.ga.gov.au /odp/publications/169_SR/chap_09/c9_6.htm (1095 words)

	Gem, Rock, and Mineral Postage Stamps Featuring Pyrrhotite (Site not responding. Last check: 2007-10-27)
		Additional Notes: Pyrrhotite forms both hexagonal and monoclinic crystals depending upon the ratio of iron to sulfur in the specimen.
		Technically, pyrrhotite should be described as two, separate mineral species--one for each crystal system due to these differences--however this has not been done since the two forms are commonly intermixed in the same specimen.
		Pyrrhotite is weakly magnetic--a property which is important in distinguishing it from other minerals that have a similar appearance.
	stampmin.home.att.net /pyrrhotite.htm (107 words)

	Magnetic field reversals (Site not responding. Last check: 2007-10-27)
		The pyrrhotite to magnetite ratio and secondary overprints carried by pyrrhotite were used for geothermometry (Carpenter, 1974; Dunlop et al., 1997).
		Pyrrhotite in these rocks was identified by the unblocking temperature spectra of the NRM, thermal demagnetisation of the IRM and thermomagnetic measurments of the magnetic susceptibility.
		Isle of Skye, where pyrrhotite precipitated out of a fluid, TRM recording is hampered by the existence of large aggregates.
	www.uni-tuebingen.de /geo/gpi/ag-appel/projekte/palaeomag/ptrmpro (1927 words)

	pyrrhotite -- Encyclopædia Britannica
		It commonly is found with pentlandite and other sulfides in silica-poor igneous rocks, as at Kongsberg, Nor.; Andreas-Berg, Ger.; Trentino, Italy; and Sudbury, Ont. The variety troilite, with a composition near that of iron...
		Pyrrhotite, which typically has a bronzelike appearance and is slightly magnetic, is a common accessory mineral in mafic igneous...
		It is nearly always found with pyrrhotite and similar minerals in silica-poor rocks such as those at Bushveld, S.Af.; Bodø, Nor.; and Sudbury, Ont., Can.
	www.britannica.com /eb/article-9062069 (425 words)

	Mineral description : Pyrrhotite
		Pyrrhotite with yellow pyrite from Björkdal gold mine.
		Pyrrhotite forms in magmatic igneous deposits, especially when the rock is of basic or ultrabasic composition.
		If you have some questions, suggestions or comments you are welcome to write me a line or two.
	www.geology.neab.net /minerals/pyrrhoti.htm (109 words)

	Laboratory Studies of Pyrrhotite Oxidation
		The pyrrhotite concentrate material was studied to assess the oxidation kinetics for different conditions of temperature, pH and bacterial catalysis.
		The specific surface areas (area/mass) of selected particle size-fractions varied significantly among pyrrhotite specimens and exhibited values that were a factor of 2 to 10 times greater than those of similar size pyrite particles and 6 to 40 times greater than calculated theoretical surface areas assuming spherical smooth geometry.
		The surface area of the pyrrhotite particles is by far, the most significant parameter required to assess oxidation rates for pyrrhotite in tailings.
	www.nrcan.gc.ca /smm/canmet-mtb/mmsl-lmsm/mend/reports/1212es_e.htm (811 words)

	Bayerisches Geoinstitut Annual Report 1995 Microstructural investigations of mixed superstructures of natural ...
		Pyrrhotite is the most abundant magnetic ore mineral in the paragneissic and metabasic rock suite of the continental crust sampled by the German continental deep-drilling project (KTB), in which it formed by pre-, syn- and postmetamorphic phases of mineralization.
		The non-stoichiometry of pyrrhotite causes a deficiency of iron atoms in the Fe layers.
		Because the superstructures of pyrrhotite mostly depend on the stacking sequences of the (001)-Fe layers in c* direction, it is necessary to use c* diffraction information for the identification of pyrrhotite superstructures.
	www.bgi.uni-bayreuth.de /annual_report/1995/c_43.phtml (791 words)

	SME--VIRTUAL ATLAS OF OPAQUE AND ORE MINERALS
		Pyrrhotite (dark brown, top right) has a well developed cleavage which extends into chalcopyrite (yellow, top centre and left) and cubanite (blue-grey, centre right) areas, suggesting that chalcopyrite and cubanite are replacing pyrrhotite.
		Pyrrhotite crystals (light brown) have granular pentlandite crystals (light brown, higher reflectance, centre left) along their grain boundaries but are free of flame-like exsolution bodies of pentlandite.
		Pyrrhotite is intergrown with chalcopyrite (yellow, centre) and encloses subhedral magnetite (grey, top left), some of which is lightly etched (left bottom).
	www.smenet.org /opaque-ore/plate12.htm (342 words)

	Pyrrhotite varieties from the 9.1 km deep borehole of the KTB project -- Posfai et al. 85 (10): 1406 -- American ...
		Pyrrhotite varieties from the 9.1 km deep borehole of the KTB project -- Posfai et al.
		According to bulk thermomagnetic measurements, pyrrhotite grains from 9080 m are antiferromagnetic at room temperature; we attribute this behavior to the dominance of the disordered 1C type.
		In the upper section of the hole (at 564 and 2325 m) several pyrrhotite varieties occur, but the 4C type is most common, in agreement with the ferrimagnetic character of most pyrrhotite grains.
	ammin.geoscienceworld.org /cgi/content/abstract/85/10/1406 (293 words)

	Short Course Notes
		Throughout the discussion, superlattice dimensions a and c of pyrrhotites and related phases are presented in terms of A and C, the dimensions of the simple hexagonal subcell with a NiAs (1C) structure.
		It is found either with troilite or with low-temperature pyrrhotites (Kullerud, 1967) in a wide variety of geological environments including: fl iron sulfide muds, contact metasomatic and hydrothermal deposits, bedded cupriferous iron sulfide deposits within metamorphic rocks, in certain ultrabasic rocks and in several lunar rocks (Zoka et al, 7.973).
		It occurs as exsolution lamallae in monoclinic pyrrhotite (Bennett et al, 1972) and in geodes which have fluid inclusion filling-temperatures of 25 to 40°C,suggesting that it is a phase stable only at low temperatures.
	www.minsocam.org /MSA/collectors_corner/arc/scn1.htm (1934 words)

	RESULTS FROM LEG 169
		Larger massive sulfide clasts in the turbidites are composed predominantly of interlocking bladed pyrrhotite with pyrite, sphalerite, and chalcopyrite (Goodfellow and Franklin, 1993; Fouquet, Zierenberg, Miller, et al., 1998).
		Intergrown isocubanite-chalcopyrite and pyrrhotite are the predominant vein-filling minerals with minor to trace amounts of sphalerite and late-stage marcasite or pyrite ±; magnetite replacing pyrrhotite.
		This is consistent with the lack of chimneys, an indication of focused fluid discharge, and the occurrence of thin, high-temperature pyrrhotite crusts on the sediment observed during submersible dives (Zierenberg et al., 1993).
	www-odp.tamu.edu /publications/169_SR/chap_10/c10_3.htm (8952 words)

	[No title]
		Pyrrhotite is non-stoichiometric and the magnetism is dependent upon the amount of non-stoichiometry.
		Pyrrhotite is associated with this mineralization.) In the former case, pyrrhotite is always associated with pentlandite, chalcopyrite, and magnetite.
		In the latter case, pyrrhotite is associated with chalcopyrite, sphalerite, pyrite ±galena, magnetite, and arsenopyrite.
	www.d.umn.edu /~pmorton/geol2300/classnotes/sulfides.doc (943 words)

	Paleomagnetism of the Notch Peak contact metamorphic aureole, revisited: Pyrrhotite from magnetite+pyrite under ...
		In part, the pyrrhotite formed by in situ reduction of magnetite by pyrite and organic compounds; it could not have been formed by the large-scale introduction of reducing fluids, as isotopic evidence indicates that these metalimestones remained impermeable.
		As magnetite destruction and pyrrhotite formation extends into rocks that are not obviously metamorphosed, the reactions responsible could proceed at very low (less than ∼200°C) temperatures, and the feasibility of such low-temperature reactions in a closed system is shown by detailed thermodynamic calculations.
		This study demonstrates that under reducing conditions in the presence of sufficient pyrite, pyrrhotite can form at the expense of magnetite under very mild conditions; indeed, magnetite may be destroyed merely by deep burial.
	www.agu.org /pubs/crossref/2003/2002JB002386.shtml (344 words)

	Subaqueous Deposition of Tailings in the Strathcona Tailings Treatment System
		The pyrrhotite tailings used during the program consisted predominantly of pyrrhotite (92-95%), with lesser amounts of magnetite and non-opaque minerals.
		For each of these parameters, the higher values were associated with the liquid portion of the pyrrhotite tailings and the lower values with the liquid portion of the SM tailings.
		Based on the data collected to date, it was concluded that subaqueous disposal of pyrrhotite tailings, with a shallow cover layer of sediment substrate from the Strathcona tailings treatment system, would be the most effective of the deposition scenario studied for reducing acid generation.
	www.nrcan.gc.ca /mms/canmet-mtb/mmsl-lmsm/mend/reports/pca1es_e.htm (1104 words)

	Pyrrhotite - Reciprocal Net Common Molecules (Site not responding. Last check: 2007-10-27)
		Pyrrhotite is a magnetic mineral whose crystals are an opaque bronze color.
		The sources of pyrrhotite are quite diverse, being found in Sudbury, Ontario; Ducktown, Tennessee; Chihuahua, Mexico; Russia; Germany and Brazil.
		Industrially, pyrrhotite is used as an ore of iron and sulfide.
	www.reciprocalnet.org /recipnet/showsample.jsp?sampleId=27343882 (155 words)

	Untitled Document
		Pyrrhotite is brownish-bronze colored mineral with a fl streak.
		Pyrrhotite is the next most common magnetic mineral to magnetite.
		Pyrrhotite is commonly associated with basic igneous rocks.
	s01.middlebury.edu /GL211A/STUDENTS/SulfideMinerals/Beal1.htm (703 words)

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