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Anthophyllite series

Posted by Olav Revheim  
Anthophyllite series
September 12, 2011 01:03PM
    
First Draft




Click here to view Best Minerals A , and here for Best Minerals A to Z and here for Fast Navigation for finished Best Minerals articles.

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Anthophyllite:
Mg2Mg5Si8O22(OH)2

Ferro-anthophyllite:
Fe2Fe5Si8O22(OH)2

Protoanthophyllite:
Mg2Mg5Si8O22(OH)2

Protoferro-anthophyllite:
Fe2Fe5Si8O22(OH)2

Protomangano-ferro-anthophyllite:
Mn2Fe5Si8O22(OH)2

Sodicanthophyllite:
Na(NaMg)Mg5Si8O22(OH)2

Sodic-ferro-anthophyllite:
Na(NaFe)Fe5Si8O22(OH)2

Anthophyllite 70mm wide specimen, Heřmanov, Czech republic © Vítězslav Snášel



The anthophyllite-series minerals are typical minerals in metamorphic magnesium rich rocks such as serpentinites ( metapyroxenites and metaperidoties) and Mg-rich carbonates. Anthophyllite-series minerals do not form well developed crystals, but rather fibrous crystalline masses. These masses can exceed multiple tons in weight and several m3 in volume, with individual fibres excceding multiple dm in length. The mineral specimens are not particularly interesting for collectors and specimen prices rarely exceeds 50 USD even for the most “attractive” specimens.

Anthophyllite has previously been mined as a source of asbestos, with the Paakilla district in Finland as the largest producer. Significant health issues has been reported. Today anthophyllite are not mined, but can still be a problem when it occurs in larger masses in quarries operated for other rocks.

Anthophyllite is an ortho-amphibole with an orthorhombic crystal structure. The basic building block of the anthophyllite will still be the same amphibole SiO4 double chains as for its monoclinic polymorph cummingonite. For the clino-amphoiboles, all the SiO4 tethraeders are oriented in the same direction, whereas for the orthoamphiboles, the SiO4 tetraeders next to each other are oriented in opposite directions, thus giving different crystal symmetry. The Protoamphiboles are still orthorhombic in their symmetry, but with the alternating SiO4 tetraders arranged in pairs, thus giving a unit cell dimension only half that of their orthorhombic polymorphs.

These alternating symmetries are often represented with plus and minus signs: Cummingonite (monoclinic) has a ++++++++ SiO4 tetraeder orientation, whereas Anthophyllite(orthorhombic) has a +-+-+-+- orientation and protoanthophyllite(orthorhombic) has a ++--++-- orientation of the SiO4 tetraeders. Needless to say, these minerals are not possible to distinguish for anybody but scientists with a special interest and expensive equipment, and to me it seems unlikely that the different configurations may be consistent throughout a crystal of any size.

The relationship between the anthophyllite series, tremolite/actinolite and the cummingtonite-series is a complex one. Being of a different crystal structure, anthophyllite cannot accommodate much Ca in its crystal structure, but it often occurs together with the Calcio-amphibole tremolite. Obviously a combination of geochemical environment and pressure/temperature regime will determine which mineral(s) are being formed. The anthophyllite-series minerals appears to be the preferred minerals in environments with a steep H2O or temperature gradient; hence it’s common occurrence in shear zones or as Heřmanovské balls.

Literature:

G. V. Gibbs, F. D. Bloss, H.R. Shell (1960): PROTO-AMPHIBOLE, A NEW POLYTYPE, The American Mineralogist, vol 45, Sept.-Oct issue

William Alexander Deer,Robert Andrew Howie,J. Zussman: Rock-forming minerals, Volum 2


Anthophyllite
Czech Republic
Moravia (Mähren; Maehren), Vysočina Region, Velké Meziříčí, Heřmanov

Anthophyllite 10x7 cm specimen © G. van der Veldt



Antophyllite occurs here in irregular “ball” shaped nodules. The nodules are layered with a phlogopite core, a thin intermediate talc layer with a thicker ( cm sized) anthophyllite (and tremolite?) layer surrounded by dark mica (“biotite”). These “Hermanov balls” are normally between 3 and 9 cm in size and can give quite attractive mineral specimens. They appears to be sufficiently common to meet market demand, and are generally sold for considerably less than 100 USD (2011).

The anthophyllite bearing nodules are found in the contact zone between serpentinised ultra-basic rock and an intruding granitic pegmatite. How these nodules has formed is not understood.

Literature:

Kryštof Turek(2008): CHARAKTERISTIKA ULTRABAZICKÝCH UZAVŘENIN V HORNINÁCH MOLDANUBIKA, Diplomová práce, Přírodovědecká fakulta, MASARYKOVA UNIVERZITA BRNO

www.hermanov.info/texts/koukola-kolem-hermanova.pdf

Anthophyllite
Finland
Eastern Finland Province, Tuusniemi, Paakkila

Anthophyllite 4 cm FOV © Leon Hupperichs


The Paakkila quarry is located a few kilometres beyond the limit of the town of Outokumpu in the direction of Kuopio . Anthophyllite occurs as asbestiform fibres in ellipsoidal bodies and lenses. Arounbd 50 of these lenses have been found, averaging 5000 to 7000 cubic metres. Asbestos from these lenses has been mined for over 4000 years, and modern industrial mining from 1918 to 1975 yielded som 350.000 tonnes of asbestos. Medical studies have shown extensive heath effects as a result of the mining operations.

The Paakkila asbestos deposits are associated with serpentinite intrusives of the Karelian orogeny. The major rock types at Paakkilannierni are mica gneiss and granite .The asbestos lenses display a zonal structure, which is manifested by the variation in mineralogical composition from the contacts of the lenses with the host rock towards the centre . The zones are mica, tremolite/actinolite, talc and asbestos, with an asbestos serpentine core .

Literature:

Benjamin Levadie (ed) (1984 ) definitions for asbestos and other health-related silicates, a symposium. Astm Special Technical Publication

GUNNAR HILLERDAL, ANDERS ZITTING, ALEXANDER HW van ASSENDELFT,TIMO KUUSELA (1984), Rarity of mineral fibre pleurisy among persons exposed to Finnish anthophyllite and with low risk of mesothelioma, Thorax vol 39:608-611

AARTO HUHMA (1975): Outokummun, Polvijarven ja Sivakkavaaran kartta-alueiden kalliopera, Summary: Precambrian rocks of the Outokumpu, Polvijarvi and Sivakkavaara map-sheet areas, Geologinen tutkimuslaitos, Espoo


Anthophyllite
Italy
Trentino-Alto Adige, Bolzano Province (South Tyrol), Passiria Valley (Passeier Valley), Monteneve Mine (Schneeberg Mine)

Anthophyllitic amphibole 7x6x5 cm specimen© Simone Citon


Monteneve/Schneeberg is one of the highest altitude mining districts in Europe, and silver coins from here was documented as "ARGENTUM BONUM DE SNEEBERCH “ as early as 1237. The deposits may have been exploited as early as pre-historic times. The mining operations ceased in 1985, but it is still in use as a tourist attraction.

During the centuries, a network of adits, shaft and tunnels penetrate the mountains, and the locality should possibly be split into several sublocalities.

The ore consists mainly of argentiferous galenite, sphalerite and chalcopyrite in addition to a wide array of associated minerals. The lens shaped ore bodies are found in a sequence of metasedimentary and metavolcanic rocks including garnet-mica schists, marbles, amphibolites and quartzites. Anthophyllite is found as a fibrous crystals with garnet, tremolite and sphalerite as porfyroblasts in a dark schist rich in organic material in conjuction with the ore mineralization. The amphibole minerals can still be found as fibrous crystals in the mine dumps, sometimes together with well formed garnets.

Literature:

V. Mair, F. Vavtar , H. Schölzhorn & D. Schölzhorn(2007) DER BLEI-ZINK-ERZBERGBAU AM SCHNEEBERG, SÜDTIROL, MITT.ÖSTERR.MINER.GES.


Anthophyllite
Italy
Trentino-Alto Adige, Bolzano Province (South Tyrol), Passiria Valley (Passeier Valley)

Anthophyllitic amphibole 7x6x5 cm specimen© Marco Barsanti


There are several ore deposits in the vicinity of the Monteneve/Schneeberg mine, some of them expoited, some not. These smaller ore bodies belongs to the same geological horizon as the main mine, and anthophyllite/tremolite should be present also at these locations. Whether or not the pictured specimen are found in the main mine (or it's dumps) or in one of the smaller orebodies in the same area is not easy to say.


Anthophyllite
Gedrite
Norway
Aust-Agder, Risør

Anthophyllite-gedrite, FOV 50mm© Jan Kihle


Risør is one of many localities in the Bamble formation where anthophyllite-gedrite can be found. The Bamble formation is a rock sequence formed during the Sveco-Norwegian orogeny (1,1-1,5 Ga). Anthophyllite and gedrite is found in aluminuos amphibolites and metasedimentary gneisses together with cordierite, Mg-rich mica +/- plagioclase and other amphibole group minerals. The composition of the orthoamphiboles are always near the Mg end- member, but the Al content may vary. Beeson (1978) publishes 17 analysis' of orthoamphiboles from different rocks in this area and found an Al content in the T position varying from 0,43 to 1,52 apfu. The borderline between anthophyllite and gedrite lies at Al=1 in the T-position.

The exsolved iridescent Gedrite-Anthophyllite crystals from this locality occurs solely with pristine cordierite, fine grained rutile, a Mg-Ti rich biotite and less commonly albitic plagioclase. Sizes may reach 10 cm in length. Well defined crystals showing crystal faces are very rare, more commonly these orthoamphiboles tend to form irregular spray aggregates. A terminated single crystal from this occurrence (hand specimen) is on display in the mineral gallery of the Mineralogical-Geological museum in Oslo.

Literature:

R. Beeson(1978): The Geochemistry of Orthoamphiboles and Coexisting Cordierites and Phlogopites From Sout Norway. Contributions to Mineralogy and Petrology 66 5-14.

Bernard Bingen, William J. Davis, Michael A. Hamilton, Ane K. Engvik, Holly J. Stein, Øyvind Skår and Øystein Nordgulen
(2008): Geochronology of high-grade metamorphism in the Sveconorwegian belt, S. Norway: U-Pb, Th-Pb and Re-Os data. Norwegian Journal of Geology


Anthophyllite
Gedrite
Norway
Aust-Agder, Akland, Moland

Anthophyllite-gedrite, 3cm crystal© Olav Revheim


This locality has also produced anthophyllite/gedrite specimen as individual crystals and crystalline masses up to minimum 10 cm. They where found in a plagioclase rich gneiss with cordierite and phlogopite. The geology at this location is similar to the previous entry.

Anthophyllite
Norway
Nordland, Rana, Altermark Area, Altermark talc mine

Anthophyllitic amphibole 5 cm tall specimen© Jorge M. Alves


The Altermark talc mine has been a of talc since around 1934. The mine has been mined from four different levels, and the accumulated production is estimated to 1 mill. tons. The remaining reserves are considerable.

This is a metamorphosed ultramafic intrusion. During the metamorphisis to high greenschist/low amphibolite facies in the caledonian orogeny, the original dunites/pyroxenites and rodingites(?) are now zoned with a serpentinite core surrounded by a serpentinite/carbonate/talc and a carbonate/talc layer. A thin talc schist zone can be found between the carbonate/talc layer and the surounding "blackwall" rocks.

Amphiboles, in particular green chromian actonlite can be found in well formed crystals up to 10cm, but also light colored amphiboles can be found in fibreous mats up to 10-15cm, as overgrowth on actinolite crystals and white "stars" like the one pictured in sizes up to 4-5cm. Karlsen and Birtel identifies both anthophyllite,cummingtonite and tremolite as occuring amphiboles, although Birtel seems to consider anthophylite rarer than Karlsen, but without really taking interest in these amphiboles.

Due to the occurance of multiple light colored amphibole species, a sepcimen should not be named unless accompanied by analytical data.

Literature:

Altermark, THE INDUSTRIAL MINERAL DATABASE at Norwegian Geological Survey.

Karlsen, T.A., Rian, E. & Olesen, O.: 2000: Overview of talc resources and reserves in the Altermark talc province,
northern Norway and possible uses of the talc ore. Norges geologiske undersøkelse Bulletin, 436, 93-102.

Sandra Birtel (2002): Fluid-rock interaction on alpine- type ultramafic rocks from the Norwegian Caledonides. Dissertation zur Erlangung des Doktorgrades der Geowissenschaftlichen Fakultät der Albert-Ludwigs Universität Freiburg i.Br.


Anthophyllite
USA
Massachusetts, Hampshire Co., Pelham , Pelham asbestos mine

Anthophyllite, 10cm specimen © Michael Shaw



The Pelham asbestos mine was mined for anthophyllite asbestos in the second half of the 19th century. The anthophyllite was found as veins and pods penetrating a methamorphosed ultramafic olivine/pyroxene rock. The asbestos production has been estimated to "several hundred tons". Anthophyllite was found as fibrous asbestos with individual fibres up to 1m long, and could still be found in the abandoned quarry up until the 1980-ties. I do not know the status today.

The Pelham asbestos mine is one of many similar ultramafic bodies in the area, methamorphosed to amphibolite facies in the Acadian orogeny (325-400ma). Tracey et. al. describes anthophylite also from other locations in the vicinity ( in relative terms) of Pelham.

During the methamorphosis, an interesting mineral assemblage has formed in the border zone between the ultramafic anthophyllite bearing rock and the surronding quartz-rich (metasedimentary) gneiss, and the mineralogy and the Pelham quarry is vividly described by Emerson.

Literature:

Benjamin, Kendall Emerson (1898): GEOLOGY OF OLD HAMPSHIRE COUNTY, MASSACHUSETTS COMPRISING FRANKLIN, HAMPSHIRE, AND HAMPDEN COUNTIES. Monographs of the Unites States Geological survey, Volume XXIX

Earl V. Shannon (1919): FAMOUS MINERAL LOCALITIES: THE PELHAM ASBESTOS MINE, MASSACHUSETTS. American Mineralogist, Vol 4 pp37

David R. Veblen (1980): Anthophyllite asbestos: microstructures, intergrown sheet silicates, and mechanisms of fiber formation. American Mineralogist, Volume 65, pages 1075-1086,

Robert J. Tracey, Peter Robinson and Robert A. Wolff (1984): Metamorphosed ultramafic rocks in the Bronson Hill anticlinorium, central Massachusetts. Americal Journal of Science Vol 284, p 530-558


Anthophyllite
USA
Pennsylvania, Delaware Co., Middletown Township, Elwyn, Mineral Hill, Crump's quarry

Anthophyllite, 6,5 cm specimens © M.Heintzelman


Crumps Quarry is one of the many anthophyllite locations in serpentinites the North-Eastern USA. The serpentinites are believed to be metamorphosed enstatite-rich pyroxenites and peridotites originating from the oceanic crust between the ancient Iapetus ocean. These rocks was metamorphosed in the Acadian orogeny.

Anthophyllite ( together with tremolite) can be found in many of these serpentine rocks as asbestiform fibres in thin veins in shear zones in the serpentinite host rock. The anthophyllite fibres can be up to 18 in. long, and asbest has been a by product during 19th and early 20th century operations of these quarries.

"This specimen was collected at some point in the 1980's by Keith Robertson, then president of the Delaware Mineralogical society (prior to the prohibition on collecting in the area). At the time there were still a few accessible exposures. Roger Mitchell of the Delaware Co. Institute of Natural Science... expressly familiar with materials from Mineral Hill, has not felt the need to question it's identity." Mark Heintzelman 2011

Literature:

NANCY C. PEARRE and ALLEN V. HEYL, JR.(1960): Chromite and Other Mineral Deposits in Serpentine Rocks Of the Piedmont Upland Maryland, Pennsylvania And Delaware, CONTRIBUTIONS TO ECONOMIC GEOLOGY GEOLOGICAL SURVEY BULLETIN 1082-K

E.B. Alexander (?): Serpentine Geoecology of the Appalachian and Ouachitan Orogen

Protoanthophyllite
Japan
Honshu Island, Chugoku Region , Okayama Prefecture , Niimi City, Takase mine

Protoanthophyllite, 0,25cm FOV © 2008, JGW



Protoanthophyllite has been described from the Takase ultramafic complex in Japan. It occurs as prismatic crystals up to 5 mm in length in a thermally altered serpentinite that experienced contact metamorphism. The protoanthophyllite is associated with forsterite, talc, serpentine minerals, chlorite, chromian spinel, magnetite, pentlandite, and calcite. Some protoanthophyllite crystals contain minute lamellae of anthophyllite.

Literature:

Hiromi Konishi, Thomas L. Groy, István Dódony, Ritsuro Miyawaki, Satoshi Matsubara and Peter R. Buseck (2003): Crystal structure of protoanthophyllite: A new mineral from the Takase ultramafic complex, Japan, American Mineralogist; November-December; v. 88; no. 11-12; p. 1718-1723


Protomangano- ferroanthophyllite
Japan
Honshu Island, Kanto Region , Tochigi Prefecture , Kanuma City , Awano , Nippyo mine (Yokoneyama)

Protomangano- ferro-anthophyllite, 2,9cm FOV © R. Tanaka


Protomangano-ferroanthophyllite has been found as light brownish yellow agicular crystals up to 15 mm and forms aggregates resembling wheat sheafs. Some of the smaller crystals are colourless and transparent. The mineral is found with pyroxmangite, rhodonite, spessartine and rhodochrosite in a metamorphosed and metasomatic metasedimentary manganese deposits.

Literature:

Shigeho Sueno, Shigeru Matsuura, Michiaki Bunno, Masanori Kurosawa ( 2002): Occurance and crystal chemical features of protoferro-anthophyllite and protomangano-ferro-anthophyllite from Cheyenne Canyon and Cheyenne Mountain U.S.A. and Hirukawa-mura, Suisho-yama and Yokone-yama, Japan. Journal of Mineralogical and Petrological Sciences, Volume 97, page 127-136


Olav Revheim October 2011

Click here to view Best Minerals A , and here for Best Minerals A to Z and here for Fast Navigation for finished Best Minerals articles.



Edited 24 time(s). Last edit at 03/26/2012 06:28PM by Rock Currier.
avatar Re: Anthophyllite series
March 23, 2012 10:47AM
Olav,
I might suggest that at the top of your articles like this one that you should make each of the mineral names you list an active link to the species page for that mineral. I have linked the first one, Anthophyllite to the Anthophyllite species page.

I would also suggest that when you are finished with your first draft of an article that you create a Best Localities link on the species page for each of the minerals in the Anthophyllite series.

Here are instructions on how to do that:

You need to add the best minerals Message number to the second Message ID field that is located on the edit page for the species. There are two Message ID fields on the species edit pages, of which only the second one is valid. They are both located neat the top of the Species Edit page, 5th and 12th fields from the top. For example the URL for the Best Minrals Acanthite article is: [www.mindat.org]. The Message number for this article is 121132. You will need to enter this number into the second Message ID field so that when you click on Acanthite link in the Best of Species box in the Best Localities for Acanthite section of the Acanthite edit page, it will take you to the Best Minerals Acanthite article. When you enter the Message number of the Best Mineral article in the edit field of a particular species in the second Message ID field causes the Best Localities for xxxxx section to appear in the species description page and the field with the name Best of Species to appear with the name of the species. This link is located about three quarters of the way down the page. Some Best Mineral articles exceed 60,000 characters and have more than one Best Minerals articles about them and therefore more than one Message ID number. You can enter more than one number separated by a coma, but the Message ID field will retain and act only on the first Message ID number. Entering a Message number in the first Message ID field on the species edit page does nothing. Entering the Message ID number in the second field also places it in the first Message field after you have clicked the submit button.

Rock Currier
Crystals not pistols.



Edited 1 time(s). Last edit at 03/23/2012 11:09AM by Rock Currier.
Re: Anthophyllite series
March 23, 2012 12:47PM
    
Rock,

I don't think I'm authorized to make changes on the species pages cause I cannot find any edit button for editing species pages anywhere.

Olav
avatar Re: Anthophyllite series
March 23, 2012 06:22PM
Olav,
OK, Im checking into that.
Rocik

Rock Currier
Crystals not pistols.
avatar Re: Anthophyllite series
March 23, 2012 06:44PM
I think I have just given you permission to edit minerals. Try it now and see if you can edit a mineral and make the link to your articles.

Rock Currier
Crystals not pistols.
avatar Re: Anthophyllite series
March 23, 2012 07:11PM
Olav,
At the top of your article, I think you are missing the name Protoanthophyllite although the species number is there. I have made the attachments to the species pages for the anthophyllite series but left it to you to correct? the Protoanthophyllite entry at the top and to link it with the species page if you can.

Rock Currier
Crystals not pistols.
Re: Anthophyllite series
March 24, 2012 09:11AM
    
Rock.

Thanks, I made it work. I'll work my way through the articles. smiling smiley

Also, is it OK if I harmonize the way the formulas are written, add literature references and add the subgroup for each species?

Olav
avatar Re: Anthophyllite series
March 24, 2012 09:59AM
Olav,
Of course you can do anything you want. You are a reasonable guy, and hopefully we can get some of the guys who devised the nomenclature to work with us on this to make sure we don't screw it up. If I were you I would find out who some of these guys were and approach them directly.I bet if you asked them, they would help, especially if you would show them what we are trying to accomplish here. They could probably also tell you if the thinking on these kinds of minerals is likely to change the nomenclature in the future.
I am going through all the articles and making links on the species pages to the best minerals articles. There are some articles where the species are too big to fit into these 60,000 character fields in in those cases I am only referencing the first article for those species and trust that the links at the top of the page will direct the user to the rest of the articles. Example: Azurite. Some minerals like Quartz, Calcite, Gypsum, Baryte and Fluorite are even bigger where each country has its own forums for that mineral. In those cases I will create a fast navigation page for those minerals and direct the user to that page from the mineral species page like I did for Baryte.

Rock Currier
Crystals not pistols.
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