[meteorite-list] Fwd: Re: Fusion Crust on Irons--Not
From: cdtucson at cox.net <cdtucson_at_meteoritecentral.com>
Date: Thu, 19 Nov 2009 18:27:44 -0800 Message-ID: <20091119212744.C2BJ7.253273.imail_at_fed1rmwml31> > Fred, no problem.see link; > > http://adsabs.harvard.edu/abs/1990Metik..49..115M > > Carl > -- > Carl or Debbie Esparza > Meteoritemax > > > ---- debfred at att.net wrote: > > Carl, I need some help here. Which one of these elements or minerals is in the silicate group? > > Sikhote-Alin is a coarse iron octahedrite. Its composition is as follows: 5.9% nickel, 0.42 % cobalt, 0.46% phosphorus, 0.28% sulfur, smaller amounts of germanium and iridium, and the remainder (approximately 93%) is iron. The following minerals are present: taenite, plessite, rhabites, troilite, chromite, kamacite, and schreibersite crystals. ... > > Regards, Fred > > -------------- Original message ---------------------- > > From: <cdtucson at cox.net> > > > > > If I'm not mistaken. The crust shown on Sikhotes may well be a true fusion crust > > > because sikhote does contain some silicate minerals within it. > > It is the irons without silicates that cannot produce a true fusion crust. And > > as Elton said, Nobody has ever shown one of these non-silicate irons with fusion > > crust. In fact the two examples shown are the only examples I have ever seen of > > any type of iron meteorite with fusion crust, not counting true silicated irons > > > of course. > > Does anyone have other pictures of any irons with fusion crusts to share? Thanks > > > Carl > > > -- > > > Carl or Debbie Esparza > > > Meteoritemax > > > > > > > > > ---- ensoramanda at ntlworld.com wrote: > > > > Hi Elton, > > > > > > > I think it is that thin coating of magnetite that most folks are calling a > > > fusion crust on fresh irons...what else can it be called? > > > > > > > As you say, unfortunately it is quite fragile and on most irons it flakes or > > comes off after very little time in our climate, so most of those wonderful > > > looking sikhote alins at the shows have actually been cleaned and treated and > > > have lost the magnetite 'fusion crust'. I have seen many with remnants which you > > > can see still peeling off but rarely in their pristine matt grey original state. > > > Also, as you say, those flow lines can be still present mostly underneath when > > > the magnetite/crust has gone but are I think much more detailed and sharp when > > > the magnetite coating is fresh. > > > > > > > > If you know of a different name/term to call the magnetite coating on fresh > > > irons other than fusion crust then I am sure we would all like to know what we > > > should call it? > > > > > > > > Regards, > > > > > > > > Graham > > > > > > > > > > > > > > > > ---- MEM <mstreman53 at yahoo.com> wrote: > > > > > Stopping in a few minutes to state again that all this discussion about > > > fusion crust on irons is right next to unicorns postulations. Everyone says > > > that fusion crust on irons exists but no one can come up with the proof. > > > Non-silicate bearing irons DO NOT/CANNOT have FUSION crust: they have a very > > > fragile magentite micro-crystal "film" and they have an ablation surface but, > > > they can't by definition have a "fusion crust" and no matter whom the expert > > > quoted they still do not have a fusion crust. A fusion crust has to have a > > > silicate source to for the glass component of the crust-- Nada, Nix, No How. > > > > > > > > > > Both silicate and non-silicate meteorites have an ablated/ablation surface, > > > and they can show flight features--but not all meteorites have a fusion crust. > > > I have some OCs which have flow lines UNDER the fusion crust remnants. > > > > > > > > > > If anyone still defends the presence of fusion crust on (non-silicate > > > bearing) irons then show me the "crust"...can't?..ok show me the glass? .... > > > right then-- no photos, no thin sections, no micro graphs???......And while > > > there was one close up of an ablated surface showing soft wavy lines of briefly > > > melted metal that was aligned to aerodynamic vectors--This does not fusion crust > > > make. > > > > > > > > > > Unlike in politics and public opinion, in science, no matter how often an > > > untruth is repeated it doesn't become "truth" by majority belief. But science, > > > being a human endeavor, sometimes can find itself "off track" and when it does > > > it accepts the error and gets back on track. > > > > > > > > > > Elton > > > > > ______________________________________________ > > > > > http://www.meteoritecentral.com > > > > > Meteorite-list mailing list > > > > > Meteorite-list at meteoritecentral.com > > > > > http://six.pairlist.net/mailman/listinfo/meteorite-list > > > > > > > > ______________________________________________ > > > > http://www.meteoritecentral.com > > > > Meteorite-list mailing list > > > > Meteorite-list at meteoritecentral.com > > > > http://six.pairlist.net/mailman/listinfo/meteorite-list > > > ______________________________________________ > > > http://www.meteoritecentral.com > > > Meteorite-list mailing list > > > Meteorite-list at meteoritecentral.com > > > http://six.pairlist.net/mailman/listinfo/meteorite-list > > > > > > > > > > Received on Thu 19 Nov 2009 09:27:44 PM PST |
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