[meteorite-list] Is Brahin a ruster ? Campo?

From: jbaxter112_at_pol.net <jbaxter112_at_meteoritecentral.com>
Date: Wed Feb 9 16:30:40 2005
Message-ID: <42605.10.250.10.1.1107984631.squirrel_at_sq05.pol.net>

Hi Martin,

As the subject of rusting Campos, new and old, came up I thought I would
point out that Marvin Killgore at Southwest Meteorite Lab sold me a
gorgeous new Campo slice with nice silicate inclusions two years ago and
it has not a hint of rust. I know he has at least one slice remaining as
he had it on display in Tucson. The new Campo material Marvin has seems to
be really nice stable material and the silicate inclusions add interest.

Regards,
Jim Baxter

> Yes indeed one never can be sure.
> First one can't make any individually forecast for a single piece, the
> tendency to rust is different from specimen to specimen from one and the
> same find, obviously it depends how much chlorine it absorbed. Only the
> general tendency may predicted.
> A friend of mine had an etched Campo, completely untreated and not
> stabilized, which was stable like wood for 15 years (thus not a
> representative of the so called "New" Campos), while the gross of the
> Campos I heard of from my collectors rusted away like hell, no matter
> whether "New" or old.
> Otherway round, I met once on a show a seller, who had a large box full
> of Gibeons, all despite being oiled with messy rust traces.
> I for my own keep cutting material for a certain time in quarantine to
> see, if a coating will be necessary after preparation and recommend in
> general to the new collectors, first to be aware, that every iron can
> rust and second, to keep the finger away on the beginning from such
> problematic irons like Campo, Nantan or Dronino, although they are by
> far the cheapest meteorites, to avoid frustrations.
>
> Now with Brahin, I wanted to line out, that a carefully sealed one, even
> if it's not so perfect pretty looking, would be the best and I wanted to
> share my experience with the both main supplier of Brahin in US-ebay, as
> Brahin will be always the first choice for a beginning colletor, if
> he/she wants to own a pallasite, as it is so silly cheap at the moment.
> (Anyone to remember, how the Brahin price was 15 years ago?) :-).
>
> Thus again, those from Afanasjev cometshop were extremely stable and
> from Koutyrev finmet I heard only the best.
>
> Cheers!
> Martin
>
> PS: Most stable pallasite I ever had, unstabilized, uncoated, stored
> without dessicant
> was Imilac. Also a beauty!
> Cheapest and best available at the moment through Sergej Vassiliev &
> Moritz Karl. Guess something around 15$/gm for translucent slices.
>
> PPS: I had a tiny Admire from Buehler many years ago. It's still in good
> condition.
>
> ----- Original Message -----
> From: "J?rn Koblitz" <koblitz_at_microfab.de>
> To: "Martin Altmann" <Altmann_at_Meteorite-Martin.de>; "Lars Pedersen"
> <lbp_at_privat.tdcadsl.dk>; <meteorite-list@meteoritecentral.com>
> Sent: Tuesday, February 08, 2005 2:04 PM
> Subject: AW: [meteorite-list] Is Brahin a ruster ?
>
>
> Hi List,
>
> back in the 1980s, I got a large, beautiful Admire slice. I kept it at
> low humidity and also added corrosion inhibitor to the bag in which the
> slice was wrapped in. During the first 10 years I checked for signs of
> rust from time to time. It was okay, no rust, very stable. So, I kept it
> alone (same storage conditions) until one year ago, when I look at it
> again. Well, the pallasite was in the state of disintegration, heavily
> rusted, olivines pressed out of the metal grid. What I want to say is,
> that even after so long time of stability, one can never be sure. I
> think, one has to check the state of such a known ruster more often. If
> any sign of rust, especially swallowing of olivine grains, one has to
> start corrective actions
> immediately (e.g. neutralization of acids, drying...). Rusting is a
> self-accelerating process, once it has started. If a meteorite is known
> as a ruster (like Brahin, Brenham, Admire), be very careful!
>
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Received on Wed 09 Feb 2005 04:30:31 PM PST