[meteorite-list] a question on fusion crust

From: Michael Farmer <meteoriteguy_at_meteoritecentral.com>
Date: Thu, 22 Mar 2007 10:29:43 -0700 (PDT)
Message-ID: <870941.93979.qm_at_web33113.mail.mud.yahoo.com>

Then we are in complete agreement. The composition of
the crust is of no matter, only that the crust was
produced and adhered to the meteorite by means of
fusion in the atmosphere.
Michael Farmer
--- Armando Afonso <armandoafonso at oniduo.pt> wrote:

> Of course it is fusion crust.
> We agree on something, finally.
> I only wanted to underline that question of the
> material beeing the same or
> not.
> Magnetite is a diferent substance, resulting of the
> combination with the
> atmosphere, and much harder than the Iron from where
> it came.
> Speaking of fake crusts on chondrites (since it can
> be done easily with a
> blowpipe) I am sure that some "enterpreneur" already
> sold one or two...
> To coat of magnetite an iron meteorite, is a bit
> more dificult to produce in
> the garage.
> Perhaps someone on the list could tell us something
> interesting about this.
> AA
>
>
> ----- Original Message -----
> From: "Michael Farmer" <meteoriteguy at yahoo.com>
> To: <meteorite-list at meteoritecentral.com>
> Sent: Thursday, March 22, 2007 5:04 PM
> Subject: Re: [meteorite-list] a question on fusion
> crust
>
>
> > Crus is crust, soft, hard, it doesnt matter. It is
> a
> > crust of material caused to be on the surface of
> the
> > object by fusion.
> > Why would iron fusion crut not be different than
> that
> > of stones? Of course it is chemically different.
> You
> > know, you can remove the fusion crust on some
> stones
> > easily as well, so what if most of the crust on
> irons
> > is softer, and can fake off easily. The subsurface
> is
> > smooth, and much more difficult for the crust to
> > adhere to.
> > Go to Vienna and check out Cabin Creek, 100%
> > blue-black fusion crust on the most beautiful iron
> > fall I have ever seen. It is not rust, nothing
> but a
> > crust caused by intense burning in the atmosphere.
> > You can debate over the chemical composition of
> the
> > heat altered layer on the surface of irons all you
> > want, but it is fusion crust.
> >
> > Michael Farmer
> >
> >
> > --- Armando Afonso <armandoafonso at oniduo.pt>
> wrote:
> >
> >> In that case, you get a vitrification of the
> >> silicates, with some inclusion
> >> of reduced iron, eventually coming from the
> >> pyroxenes or olivine, giving it
> >> the dark tone.
> >> Anyway, we are really speaking of diferent and
> new
> >> minerals.
> >> Normally that crust is harder than the meteorite
> in
> >> itself.
> >> AA
> >>
> >> ----- Original Message -----
> >> From: "Michael Farmer" <meteoriteguy at yahoo.com>
> >> To: "Armando Afonso" <armandoafonso at oniduo.pt>;
> >> <meteorite-list at meteoritecentral.com>
> >> Sent: Thursday, March 22, 2007 4:48 PM
> >> Subject: Re: [meteorite-list] a question on
> fusion
> >> crust
> >>
> >>
> >> > But made from the matrix component. burned
> >> material
> >> > from the parent body, regardless of how it is
> >> > chemically changed, same as the fusion crust on
> >> any
> >> > meteorite. Take a Eucrite like Stannern for
> >> example,
> >> > white interior, yet the fusion crust is glossy
> >> black.
> >> > That is not soot, it is chemically altered
> matrix.
> >> > Nothing more.
> >> > Michael Farmer
> >> > --- Armando Afonso <armandoafonso at oniduo.pt>
> >> wrote:
> >> >
> >> >> Obviously, it is a diferent material...
> >> >> The external fusion crust of iron meteorites
> is
> >> >> Magnetite, the result of the
> >> >> combination with the air`s oxygene.
> >> >> AA
> >> >>
> >> >>
> >> >> ----- Original Message -----
> >> >> From: "Michael Farmer"
> <meteoriteguy at yahoo.com>
> >> >> To: "Mr EMan" <mstreman53 at yahoo.com>; "Michael
> >> >> Murray"
> >> >> <mmurray at montrose.net>;
> >> >> <Meteorite-list at meteoritecentral.com>
> >> >> Sent: Thursday, March 22, 2007 4:14 PM
> >> >> Subject: Re: [meteorite-list] a question on
> >> fusion
> >> >> crust
> >> >>
> >> >>
> >> >> > This is simple.
> >> >> >
> >> >> > Fusion, the result of material burning at
> >> extreme
> >> >> > temeratures, and crust, the layer on the
> >> surface
> >> >> that
> >> >> > was not there before re-entry.
> >> >> > Thus, FUSION CRUST
> >> >> > It is quite obvious that the surface of a
> >> freshly
> >> >> > fallen iron, with the blue-black coating is
> a
> >> >> FUSION
> >> >> > CRUST.
> >> >> > It generally can't be "wiped" off. I have
> >> pieces
> >> >> in my
> >> >> > collection, Bugoslava for example, with a .5
> mm
> >> >> layer
> >> >> > of blue-black fusion crust, that survived
> >> cutting
> >> >> and
> >> >> > polishing of the meteorite, so it is not
> exacly
> >> >> > "soot". Of course the crust is the same as
> the
> >> >> parent
> >> >> > material, even on stones. How could it be of
> a
> >> >> > different material? How could an object,
> >> falling
> >> >> > through the atmosphere, get coated with
> >> anything
> >> >> but
> >> >> > it's own matrix as it burns? Yes, the
> silicates
> >> >> can be
> >> >> > altered due to heating, while irons tend not
> to
> >> >> > chemically alter.
> >> >> > Elton, I think you are about the only one in
> >> the
> >> >> world
> >> >> > that thinks fresh fallen iron meteorites do
> not
> >> >> have
> >> >> > fusion crust.
> >> >> > Michael Farmer
> >> >> >
> >> >> > --- Mr EMan <mstreman53 at yahoo.com> wrote:
> >> >> >
> >> >> >> The "soot" coating you are talking about is
> >> >> mostly
> >> >> >> freshly created magnetite (micro /nano
> >> crystals)
> >> >> >> from
> >> >> >> the oxidation of iron whilst passing
> through
> >> the
> >> >> >> incandescent phase. It adheres by
> magnetism
> >> and
> >> >> can
> >> >> >> be wiped off with rough handling. There is
> >> >> probably
> >> >> >> a
> >> >> >> carbon component however graphite turns to
> >> carbon
> >> >> >> dioxide upon burning >
> >> >> >> There are several other terms for the zone
> >> >> >> associated
> >> >> >> with "ablation" heating, one of which is in
> >> the
> >> >> >> literature: "zone of thermal alteration".
> When
> >> >> there
> >> >> >> is an oxidation coat
>
=== message truncated ===
Received on Thu 22 Mar 2007 01:29:43 PM PDT