[meteorite-list] Stones with High Troilite, Low Metal
From: Carl Agee <agee_at_meteoritecentral.com>
Date: Mon, 27 Jun 2011 06:47:53 -0600
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:
Are you sure the sulfide is all troilite?
-- 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: agee at unm.edu http://epswww.unm.edu/iom/pers/agee.html ------------------------------------------------------------- Message: 13 Date: Mon, 27 Jun 2011 00:31:45 -0400 From: Pete Pete <rsvp321 at hotmail.com> Subject: Re: [meteorite-list] Stones with High Troilite, Low Metal To: <mexicodoug at aim.com>, <meteoritemike at gmail.com>, meteoritelist meteoritelist <meteorite-list at meteoritecentral.com> Message-ID: <bay153-w42304EFE707206467A6876F8570 at 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, PeteReceived on Mon 27 Jun 2011 08:47:53 AM PDT