Re: [meteorite-list] Stones with High Troilite, Low Metal
Hi Pete, I sent you some email attachments with backscatter electron images of NWA 6588 done with our electron microprobe. Sorry, I need to find the time to put some photos on the EoM, but not yet registered! I'm am having our website and the IOM Meteorite Catalog upgraded right now, so many photos of our collection soon the come. In the photos that I sent, you can see the bright sulfides are actually two different minerals, usually in contact with each other. The pentlandite is Ni-rich iron sulfide and the pyrite is just iron sulfide (FeS2 pyrite formula, not FeS troilite). The image Relict Chondrules 2 shows a lower magnification of the overall microscopic texture of NWA 6588. All the bright spots are sulfide. You can see the porphyritic olivine chondrule in the upper right and the in the lower left is part of a barred olivine chondrule. Because of the small size of the sulfides, the best way to determine which iron sulfide(s) is present is by electron microprobe quantitative analysis or by EDS on and SEM. I was actually quite surprised when NWA 6588 turned out not to have troilite! Best regards, Carl Agee -- Carl B. Agee Director and Curator, Institute of Meteoritics Professor, Earth and Planetary Sciences MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 Tel: (505) 750-7172 Fax: (505) 277-3577 Email: a...@unm.edu http://epswww.unm.edu/iom/pers/agee.html On Tue, Jun 28, 2011 at 4:10 PM, Pete Pete rsvp...@hotmail.com wrote: Dear Carl, Doug, and List, Carl, your classification of NWA 6588 reads very close to this one! Thank you for that link. Am I sure the sulfide in mine is all troilite? Absolutely not. Is there a test for it that I can do? I'm only going by my experience of what I've seen in books, the net, and the classifieds and non-classifieds that I have here. The lack of obvious nickel or iron and (what I think is) lots of troilite is what piqued my interest enough to ask if there was similar out there. You indicated in your classification that this was indeed unusual. Since there aren't any photos of NWA 6588 online yet, I'd appreciate your viewing these of mine: http://tiny.cc/ymksq http://tiny.cc/ymksq https://skydrive.live.com/?cid=B8A3E8CAAAC69704id=B8A3E8CAAAC69704%21114sc=documents in case the tiny doesn't work. Anything that appears reflective, white, or gold coloured is what I suspect is troilite. The sulfide appears to be sprinkled into individual grains further away from concentrated areas. I didn't try to Photoshop the true colour back in, but a dark khaki grey is more accurate for the matrix. As with any meteorite, the pictures don't do the actual beauty justice ;)! Cheers, Pete Date: Mon, 27 Jun 2011 06:47:53 -0600 From: a...@unm.edu To: meteorite-list@meteoritecentral.com Subject: [meteorite-list] Stones with High Troilite, Low Metal Hi Pete, What about an LL -- with some desert weathering? The low-low metal can be converted to small Fe-oxides or veins. I recently classified Northwest Africa 6588 (LL6-an), that had only trace amounts of Fe-Ni metal. The ubiquitous sulfides present are pendlandite and stoichiometric pyrite. See metsoc 2011 abstract: http://www.lpi.usra.edu/meetings/metsoc2011/pdf/5418.pdf Are you sure the sulfide is all troilite? Carl Agee -- Carl B. Agee Director and Curator, Institute of Meteoritics Professor, Earth and Planetary Sciences MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 Tel: (505) 750-7172 Fax: (505) 277-3577 Email: a...@unm.edu http://epswww.unm.edu/iom/pers/agee.html - Message: 13 Date: Mon, 27 Jun 2011 00:31:45 -0400 From: Pete Pete rsvp...@hotmail.com Subject: Re: [meteorite-list] Stones with High Troilite, Low Metal To: mexicod...@aim.com, meteoritem...@gmail.com, meteoritelist meteoritelist meteorite-list@meteoritecentral.com Message-ID: bay153-w42304efe707206467a6876f8...@phx.gbl Content-Type: text/plain; charset=iso-8859-1 Thank you all for your responses. You're right, Doug, too ambiguous a question. I have an unclassified NWA, which I've sliced and polished. There are so many interesting features that it is the type that you never get tired of looking at under the microscope. It has what appears to be the remains of transformed chondrules; four total in about 2cm^2 surface. Three look like bit-remains of brecciated chondrules, grey and white. The other looks like a typical barred chondrule that has become completely crystallised, and has the schiller effect. A very fine grained matrix, no observable free metal as in nickel/iron, and what *appears* to be typical troilite scattered throughout. Low attraction to a neodymium magnet. The fusion crust is relatively fresh, with no chert. Quite different from the others I've got, so I was hoping to read and possibly view
Re: [meteorite-list] Stones with High Troilite, Low Metal
Jason says: You may well be right, but since troilite is typically present in rather minor concentrations in most meteorites, I have the feeling that they are not depleted in it relative to most other types...but I could be wrong. So, troilite is always pyrrhotite, but pyrrhotite isn't always troilite. Hi Jason, It is clearer IMO to think of troilite simply as the stoichiometric Fe-S endpoint of pyrrhotite; Getting polyphyletic or not is best lefts to cladists! I'm not sure of the utility of the thought you have regarding depleted: It is much better to think of this as a dynamic evolution to form the Metal-sulfides. The RELATIVE amount of stable sulfides to sulfates and oxides begins to tell good clues on the environment of formation; just as a possible rich sulfurous cloud condensate is postulated on origin. Further, the RELATIVE amount amount of troilite to pyrrhotite being quite low and in many cases nearly trace, gives more clues since it is a troilite is saturated state and has physical implications. The fact that R chondrites are so rich in sulfur yet RELATIVELY poor in troilite is the reverse of what is expected (Except for Dr. Rubin's ALH85151 which would be exciting if he has a theory to explain it, otherwise just an outlier to keep in mind). So regardless of what is in the online literature, if you want to begin forming hypotheses on any of the interesting qualities and origins of R chondrites, the least interesting thing is to compare across other classes as you suggest without a theoretical framework of what's going on within this stinky meteorites. (Sure, if you just have the rock under the loop it might be of some utility to get oriented but that still isn't convincing to me). - The only source I found in my short quest for knowledge that bothered to note how much troilite is (typically) present in R-chondrites is the NAU website. Bothered to note? - things like this are important to recognize as likely an open research opportunities - not dirt behind the refrigerator! I'm betting that the 'omission' is because that's easier than trying to explain something we Olympians don't have a clue about (or it is someone's R chondrite Nobel prize theory secret still under development), at least in the literature quickly available to us. A good place to check on the simple compositional question of being relatively troilite poor would be the analysis of the type specimen, Rumuruti ... where I'm sure it was noted. If not there, my next convenient bet would be David Weir's fantastic meteoritestudies.com site. Kindest wishes Doug -Original Message- From: Jason Utas meteorite...@gmail.com To: MexicoDoug mexicod...@aim.com Sent: Mon, Jun 27, 2011 4:01 am Subject: Re: [meteorite-list] Stones with High Troilite, Low Metal Hello Laurence, Doug, All, From an NAU site about R-chondrites: sulfide rich: pyrrhotite and pentlandite very common, minor troilite; pentlandite commonly contains Cr up to 2 wt%, troilite may contain Ni up to 3 wt% http://www4.nau.edu/meteorite/Meteorite/Rumuruti.html Which raised the question -- what is troilite and what is pyrrhotite? Pyrrhotite is an unusual iron sulfide mineral with a variable iron content: Fe(1-x)S (x = 0 to 0.2). The FeS endmember is known as troilite. http://en.wikipedia.org/wiki/Pyrrhotite So, troilite is always pyrrhotite, but pyrrhotite isn't always troilite. I don't know whether the sulfides in R-chondrites is primarily FeS where S=1 or S1, but the distinction is rarely made except in academic circles. In fact, none of the following top hits goes into any depth regarding pyrrhotite vs troilite concentrations in R-chondrites. These were the first three I found: http://adsabs.harvard.edu/full/1994Metic..29..275S http://adsabs.harvard.edu/full/1994Metic..29..255R http://www.sciencedirect.com/science/article/pii/S0009281911000237 - The only source I found in my short quest for knowledge that bothered to note how much troilite is (typically) present in R-chondrites is the NAU website. You may well be right, but since troilite is typically present in rather minor concentrations in most meteorites, I have the feeling that they are not depleted in it relative to most other types...but I could be wrong. For the purposes of Pete's visual observations, I think we can assume that he meant sulfides in general, since I doubt he has the analytical capability to tell between FeS (S=1) or FeS (S = 1 to 0.8). When I saw Pete's note, I immediately thought of R-chondrites, too...though I wonder if his stone might not be an LL-chondrite. We have a few R's, and when poked with a neodymium magnet, the pull is *barely* discernible, to the point that I might call them entirely non-magnetic if I weren't being careful. Regards, Jason On Sun, Jun 26, 2011 at 6:15 PM, MexicoDoug mexicod...@aim.com wrote: Hi Laurence Sulfur stinky yes, I don't think R chondrites are considered troilite rich
[meteorite-list] Stones with High Troilite, Low Metal
Hi Pete, What about an LL -- with some desert weathering? The low-low metal can be converted to small Fe-oxides or veins. I recently classified Northwest Africa 6588 (LL6-an), that had only trace amounts of Fe-Ni metal. The ubiquitous sulfides present are pendlandite and stoichiometric pyrite. See metsoc 2011 abstract: http://www.lpi.usra.edu/meetings/metsoc2011/pdf/5418.pdf Are you sure the sulfide is all troilite? Carl Agee -- Carl B. Agee Director and Curator, Institute of Meteoritics Professor, Earth and Planetary Sciences MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 Tel: (505) 750-7172 Fax: (505) 277-3577 Email: a...@unm.edu http://epswww.unm.edu/iom/pers/agee.html - Message: 13 Date: Mon, 27 Jun 2011 00:31:45 -0400 From: Pete Pete rsvp...@hotmail.com Subject: Re: [meteorite-list] Stones with High Troilite, Low Metal To: mexicod...@aim.com, meteoritem...@gmail.com, meteoritelist meteoritelist meteorite-list@meteoritecentral.com Message-ID: bay153-w42304efe707206467a6876f8...@phx.gbl Content-Type: text/plain; charset=iso-8859-1 Thank you all for your responses. You're right, Doug, too ambiguous a question. I have an unclassified NWA, which I've sliced and polished. There are so many interesting features that it is the type that you never get tired of looking at under the microscope. It has what appears to be the remains of transformed chondrules; four total in about 2cm^2 surface. Three look like bit-remains of brecciated chondrules, grey and white. The other looks like a typical barred chondrule that has become completely crystallised, and has the schiller effect. A very fine grained matrix, no observable free metal as in nickel/iron, and what *appears* to be typical troilite scattered throughout. Low attraction to a neodymium magnet. The fusion crust is relatively fresh, with no chert. Quite different from the others I've got, so I was hoping to read and possibly view images of similar. As I said, there are no silver metal flecks, only the dull yellow troilite-looking areas. Is it possible for nickel/iron to have this appearance, too? I had mentally eliminated that due to the low magnet attraction, but I've got lots to learn. Cheers, Pete __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Stones with High Troilite, Low Metal
Hello Laurence, Doug, All, From an NAU site about R-chondrites: sulfide rich: pyrrhotite and pentlandite very common, minor troilite; pentlandite commonly contains Cr up to 2 wt%, troilite may contain Ni up to 3 wt% http://www4.nau.edu/meteorite/Meteorite/Rumuruti.html Which raised the question -- what is troilite and what is pyrrhotite? Pyrrhotite is an unusual iron sulfide mineral with a variable iron content: Fe(1-x)S (x = 0 to 0.2). The FeS endmember is known as troilite. http://en.wikipedia.org/wiki/Pyrrhotite So, troilite is always pyrrhotite, but pyrrhotite isn't always troilite. I don't know whether the sulfides in R-chondrites is primarily FeS where S=1 or S1, but the distinction is rarely made except in academic circles. In fact, none of the following top hits goes into any depth regarding pyrrhotite vs troilite concentrations in R-chondrites. These were the first three I found: http://adsabs.harvard.edu/full/1994Metic..29..275S http://adsabs.harvard.edu/full/1994Metic..29..255R http://www.sciencedirect.com/science/article/pii/S0009281911000237 - The only source I found in my short quest for knowledge that bothered to note how much troilite is (typically) present in R-chondrites is the NAU website. You may well be right, but since troilite is typically present in rather minor concentrations in most meteorites, I have the feeling that they are not depleted in it relative to most other types...but I could be wrong. For the purposes of Pete's visual observations, I think we can assume that he meant sulfides in general, since I doubt he has the analytical capability to tell between FeS (S=1) or FeS (S = 1 to 0.8). When I saw Pete's note, I immediately thought of R-chondrites, too...though I wonder if his stone might not be an LL-chondrite. We have a few R's, and when poked with a neodymium magnet, the pull is *barely* discernible, to the point that I might call them entirely non-magnetic if I weren't being careful. Regards, Jason On Sun, Jun 26, 2011 at 6:15 PM, MexicoDoug mexicod...@aim.com wrote: Hi Laurence Sulfur stinky yes, I don't think R chondrites are considered troilite rich - are they not comparatively troilite poor? That's why I asked why he wasn't after pentlandite (and pyrrhotite) as well. The question is pretty useless trivia without more information about what the asker is after ... , Sulfur (check), Sulfides (check), Low free metals, terrestrial weathering, different alterations, they are all bundled up together. I mean, R chondrites are loaded with metal but it was oxidized after the formation, right? Considering, they are quite troilite poor unless the objective is sulfur-rich meteorites and not after troilite after all... maybe perhaps who knows Best Doug (Thinking of Mrs. Pennyfeather now!) -Original Message- From: Laurence Garvie lgar...@asu.edu To: meteorite-list@meteoritecentral.com meteorite-list@meteoritecentral.com Sent: Sun, Jun 26, 2011 8:15 pm Subject: [meteorite-list] Stones with High Troilite, Low Metal The Rumuruti (R Class) chondrites lack free metal and are sulfide rich. Laurence CMS ASU On Jun 26, 2011, at 2:19 PM, meteorite-list-requ...@meteoritecentral.com wrote: Message: 13 Date: Sun, 26 Jun 2011 14:55:17 -0400 From: Pete Pete rsvp...@hotmail.com Subject: [meteorite-list] Stones with High Troilite, Low Metal To: meteoritelist meteoritelist meteorite-list@meteoritecentral.com Message-ID: bay153-w48a18a066f0629249c54c5f8...@phx.gbl Content-Type: text/plain; charset=iso-8859-1 Sorry about that - once more with a subject: Hi, All, Is there any particular stone meteorite that has a high content of troilite and a low content of free metal? Cheers, Pete __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Stones with High Troilite, Low Metal
Sorry about that - once more with a subject: Hi, All, Is there any particular stone meteorite that has a high content of troilite and a low content of free metal? Cheers, Pete __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Stones with High Troilite, Low Metal
Lunar and Martian basalts are about 1% troilite and not very magnetic if you would like that to be a free metal consideration/measure. If not, you could always scrape off some meteoritic shale or go for highly oxidized high troilite containing iron meteorites ... like Campo or Canyon etc. -Original Message- From: Pete Pete rsvp...@hotmail.com To: meteoritelist meteoritelist meteorite-list@meteoritecentral.com Sent: Sun, Jun 26, 2011 2:55 pm Subject: [meteorite-list] Stones with High Troilite, Low Metal Sorry about that - once more with a subject: Hi, All, Is there any particular stone meteorite that has a high content of troilite and a low content of free metal? Cheers, Pete __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Stones with High Troilite, Low Metal
Mike G wrote As far as which mets have an abundance of troilite but little free metal, I cannot think of any right off-hand. Why not Albareto, which is rather low metal 'transitional'. And of course the type specimen for troilite. That would satisfy a specific rock that may or may not randomly have gotten more or less than its allotment of troilite without a handy database to sort. Pete - it would be satisfactory for many readers (or maybe just me, I guess I can't speak for the main mass) that you mention a little more about what you are after, than a generic question that is so wide open to interpretation. Might actually stimulate more discussion and be educational. For example do you mean to exclude pentlandite, and why; what's up with the question? Do you just want a meteorites oxidized in excess sulfur and/or low oxygen ... bla bla bla Kindest regards Doug -Original Message- From: Michael Gilmer meteoritem...@gmail.com To: MexicoDoug mexicod...@aim.com Cc: Meteorite-list@meteoritecentral.com Sent: Sun, Jun 26, 2011 3:50 pm Subject: Re: [meteorite-list] Stones with High Troilite, Low Metal Hi List, On rare occasion I have seen troilite nodules for sale, but not as often as graphite nodules. Recently, Ruben Garcia offered up a spectacular-looking graphite nodule. As far as which mets have an abundance of troilite but little free metal, I cannot think of any right off-hand. If it's relatively-pure troilite you are after, you might check with one of the big sellers of Campo (like Bob C.). I'm sure anyone who has tons of Campo laying around might have a troilite nodule or two. Best regards, MikeG -- - Galactic Stone Ironworks - Meteorites Amber (Michael Gilmer) Website - http://www.galactic-stone.com Facebook - http://tinyurl.com/42h79my News Feed - http://www.galactic-stone.com/rss/126516 Twitter - http://twitter.com/galacticstone EOM - http://www.encyclopedia-of-meteorites.com/collection.aspx?id=1564 - On 6/26/11, MexicoDoug mexicod...@aim.com wrote: Lunar and Martian basalts are about 1% troilite and not very magnetic if you would like that to be a free metal consideration/measure. If not, you could always scrape off some meteoritic shale or go for highly oxidized high troilite containing iron meteorites ... like Campo or Canyon etc. -Original Message- From: Pete Pete rsvp...@hotmail.com To: meteoritelist meteoritelist meteorite-list@meteoritecentral.com Sent: Sun, Jun 26, 2011 2:55 pm Subject: [meteorite-list] Stones with High Troilite, Low Metal Sorry about that - once more with a subject: Hi, All, Is there any particular stone meteorite that has a high content of troilite and a low content of free metal? Cheers, Pete __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Stones with High Troilite, Low Metal
The Rumuruti (R Class) chondrites lack free metal and are sulfide rich. Laurence CMS ASU On Jun 26, 2011, at 2:19 PM, meteorite-list-requ...@meteoritecentral.com wrote: Message: 13 Date: Sun, 26 Jun 2011 14:55:17 -0400 From: Pete Pete rsvp...@hotmail.com Subject: [meteorite-list] Stones with High Troilite, Low Metal To: meteoritelist meteoritelist meteorite-list@meteoritecentral.com Message-ID: bay153-w48a18a066f0629249c54c5f8...@phx.gbl Content-Type: text/plain; charset=iso-8859-1 Sorry about that - once more with a subject: Hi, All, Is there any particular stone meteorite that has a high content of troilite and a low content of free metal? Cheers, Pete __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Stones with High Troilite, Low Metal
Hi Laurence Sulfur stinky yes, I don't think R chondrites are considered troilite rich - are they not comparatively troilite poor? That's why I asked why he wasn't after pentlandite (and pyrrhotite) as well. The question is pretty useless trivia without more information about what the asker is after ... , Sulfur (check), Sulfides (check), Low free metals, terrestrial weathering, different alterations, they are all bundled up together. I mean, R chondrites are loaded with metal but it was oxidized after the formation, right? Considering, they are quite troilite poor unless the objective is sulfur-rich meteorites and not after troilite after all... maybe perhaps who knows Best Doug (Thinking of Mrs. Pennyfeather now!) -Original Message- From: Laurence Garvie lgar...@asu.edu To: meteorite-list@meteoritecentral.com meteorite-list@meteoritecentral.com Sent: Sun, Jun 26, 2011 8:15 pm Subject: [meteorite-list] Stones with High Troilite, Low Metal The Rumuruti (R Class) chondrites lack free metal and are sulfide rich. Laurence CMS ASU On Jun 26, 2011, at 2:19 PM, meteorite-list-requ...@meteoritecentral.com wrote: Message: 13 Date: Sun, 26 Jun 2011 14:55:17 -0400 From: Pete Pete rsvp...@hotmail.com Subject: [meteorite-list] Stones with High Troilite, Low Metal To: meteoritelist meteoritelist meteorite-list@meteoritecentral.com Message-ID: bay153-w48a18a066f0629249c54c5f8...@phx.gbl Content-Type: text/plain; charset=iso-8859-1 Sorry about that - once more with a subject: Hi, All, Is there any particular stone meteorite that has a high content of troilite and a low content of free metal? Cheers, Pete __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Stones with High Troilite, Low Metal
Thank you all for your responses. You're right, Doug, too ambiguous a question. I have an unclassified NWA, which I've sliced and polished. There are so many interesting features that it is the type that you never get tired of looking at under the microscope. It has what appears to be the remains of transformed chondrules; four total in about 2cm^2 surface. Three look like bit-remains of brecciated chondrules, grey and white. The other looks like a typical barred chondrule that has become completely crystallised, and has the schiller effect. A very fine grained matrix, no observable free metal as in nickel/iron, and what *appears* to be typical troilite scattered throughout. Low attraction to a neodymium magnet. The fusion crust is relatively fresh, with no chert. Quite different from the others I've got, so I was hoping to read and possibly view images of similar. As I said, there are no silver metal flecks, only the dull yellow troilite-looking areas. Is it possible for nickel/iron to have this appearance, too? I had mentally eliminated that due to the low magnet attraction, but I've got lots to learn. Cheers, Pete To: meteoritem...@gmail.com; meteorite-list@meteoritecentral.com Date: Sun, 26 Jun 2011 16:13:26 -0400 From: mexicod...@aim.com Subject: Re: [meteorite-list] Stones with High Troilite, Low Metal Mike G wrote As far as which mets have an abundance of troilite but little free metal, I cannot think of any right off-hand. Why not Albareto, which is rather low metal 'transitional'. And of course the type specimen for troilite. That would satisfy a specific rock that may or may not randomly have gotten more or less than its allotment of troilite without a handy database to sort. Pete - it would be satisfactory for many readers (or maybe just me, I guess I can't speak for the main mass) that you mention a little more about what you are after, than a generic question that is so wide open to interpretation. Might actually stimulate more discussion and be educational. For example do you mean to exclude pentlandite, and why; what's up with the question? Do you just want a meteorites oxidized in excess sulfur and/or low oxygen ... bla bla bla Kindest regards Doug -Original Message- From: Michael Gilmer meteoritem...@gmail.com To: MexicoDoug mexicod...@aim.com Cc: Meteorite-list@meteoritecentral.com Sent: Sun, Jun 26, 2011 3:50 pm Subject: Re: [meteorite-list] Stones with High Troilite, Low Metal Hi List, On rare occasion I have seen troilite nodules for sale, but not as often as graphite nodules. Recently, Ruben Garcia offered up a spectacular-looking graphite nodule. As far as which mets have an abundance of troilite but little free metal, I cannot think of any right off-hand. If it's relatively-pure troilite you are after, you might check with one of the big sellers of Campo (like Bob C.). I'm sure anyone who has tons of Campo laying around might have a troilite nodule or two. Best regards, MikeG -- - Galactic Stone Ironworks - Meteorites Amber (Michael Gilmer) Website - http://www.galactic-stone.com Facebook - http://tinyurl.com/42h79my News Feed - http://www.galactic-stone.com/rss/126516 Twitter - http://twitter.com/galacticstone EOM - http://www.encyclopedia-of-meteorites.com/collection.aspx?id=1564 - On 6/26/11, MexicoDoug mexicod...@aim.com wrote: Lunar and Martian basalts are about 1% troilite and not very magnetic if you would like that to be a free metal consideration/measure. If not, you could always scrape off some meteoritic shale or go for highly oxidized high troilite containing iron meteorites ... like Campo or Canyon etc. -Original Message- From: Pete Pete rsvp...@hotmail.com To: meteoritelist meteoritelist meteorite-list@meteoritecentral.com Sent: Sun, Jun 26, 2011 2:55 pm Subject: [meteorite-list] Stones with High Troilite, Low Metal Sorry about that - once more with a subject: Hi, All, Is there any particular stone meteorite that has a high content of troilite and a low content of free metal? Cheers, Pete __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit
