[meteorite-list] sharp protrusion from an iron meteorite

From: jason utas <jasonutas_at_meteoritecentral.com>
Date: Thu, 28 Feb 2013 20:31:46 -0800
Message-ID: <CAK837U1L5zQHd6kRqkQE0HLXQnL1Mn1EKSwke+3SutET57CtVw_at_mail.gmail.com>

Hello Adam, All,

Actually, Uruacu does appear to be distinct from Campo del Cielo.
Uruacu appears to be a much older meteorite that has weathered in
different conditions, and many individuals show cohenite when cut -- a
mineral I have never seen in Campo del Cielo. Generally speaking,
Campos run the full range from freshly-fusion crusted to rusty lumps,
and everything in-between. But, Campo fell within the past ~5,000
years, so we're talking about rapid weathering in a wet environment
(also why it's a ruster). Uruacu fell in a drier area, and most
individuals exhibit a much more uniform covering of shale that does
not readily flake off due to rusting. They seem to have fallen much
longer ago, and are generally more weathered due to the fact that
they've been around for longer. Uruacu generally resists rusting
better.

It would be like comparing Sikhote Alin to Henbury. No Henburies I
know of rust, but, by and large, they're not as fresh as most
Sikhotes. But some Sikhotes appear to have fallen into swampy areas
and look pretty bad -- and rust. It's hard to mix the two up.

The trouble is that I've also seen Campos sold as Uruacu, which
complicates things. Uruacu is a very old fall. Even some reputable
dealers have been selling specimens of "new Campo" (crust,
regmaglypts) as Uruacu. Very different. I assume this is due to
dishonest suppliers.

There's a stunning, fairly large Uruacu for sale at the moment. Not
mine, but I wonder if this will bring it out of the woodwork.

Regards,
Jason

> From: Adam Hupe <raremeteorites at yahoo.com>
> Date: Wed, Feb 27, 2013 at 2:59 PM
> Subject: Re: [meteorite-list] sharp protrusion from an iron meteorite
> To: Adam <meteorite-list at meteoritecentral.com>
>
>
>
> Isn't Baygorria another meteorite with a fake provenance? Basically a
> cleaned up Campo with a delaminated section protruding after a
> not-so-careful makeover. I would just tell him to seek first aid so he
> doesn't catch the dreaded Lawrencite disease.
>
> Adam
>
>
>
>
> ----- Original Message -----
> From: Randy Korotev <korotev at wustl.edu>
> To: meteorite-list at meteoritecentral.com
> Cc:
> Sent: Wednesday, February 27, 2013 2:41 PM
> Subject: [meteorite-list] sharp protrusion from an iron meteorite
>
> I recieved a well prepared letter from a fellow with a question that I can't
> begin to answer. Maybe someone on the list has seen this kind of thing
> before.
>
> He bought a Baygorria (Iron, IAB complex) from a dealer 3 years ago. He
> picked it up recently to find a metal protrusion sticking out of the thing
> that was sharp enough to prick his thumb.
>
> Here's a jpg of his scanned photo.
>
> http://meteorites.wustl.edu/baygorria.jpg
>
> What's happened here?
>
> Randy Korotev
> St. Louis
>
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Received on Thu 28 Feb 2013 11:31:46 PM PST