[meteorite-list] LOVINA REVISITED

From: info at niger-meteorite-recon.de <info_at_meteoritecentral.com>
Date: Wed, 9 Dec 2009 13:08:43 +0100 (CET)
Message-ID: <319610027.177835.1260360523963.JavaMail.open-xchange_at_oxltgw03.schlund.de>

Thank you for the new evaluation Darryl.

Although this is a regrettable development one must not forget that you took
the initial risk of acquiring such exotic material, which alone is a
remarkable?achievement. I very much hope that?this experience does not
discourage you to venture similar acquisitions in the future. If it wasn't for
people like you, most meteorites of similar caliber would never see the light of
public. Set backs are a natural part of this business and there are very few
dealers who would not subscribe to that.

Svend



? ?

Darryl Pitt <darryl at dof3.com> hat am 9. Dezember 2009 um 09:15 geschrieben:

>
> Well, I had an interesting day today....
>
> This morning I met with Roy Clarke, Linda Welzenbach, Cari Corrigan,?
> Glen MacPherson, and Tim McCoy at the Smithsonian.? ?During our get-
> together Tim made several observations as to why Lovina could very?
> well not be what it has been made out to be---which is to say, a?
> meteorite---and why more work must be done.
>
> In Tim's words....
>
> 1)? ?The sulfides are not simply troilite and appear optically to be?
> multiple phases, including one that looks like the Ni-rich sulfide?
> pentlandite.
>
> 2)? Although the presence of the octahedrons has been attributed to?
> weathering, the structure of the remainder of the meteorite shows fine?
> stringers of sulfide, not large areas that would easily weather out?
> leaving such octahedron.
>
> 3)? On one polished slice, the sulfides clearly wrap around one of the?
> indentations, rather than the cross-cutting relationship one might?
> expect from a significantly weathered iron meteorite.
>
> 4)? The composition given - high Ni coupled with moderately high Ga?
> and Ge - is difficult to reconcile with a meteorite composition.? ?
> Iron meteorites acquire high Ni concentrations through 1 of 3?
> mechanisms.? Oxidation simply changes iron to FeO, leaving Ni behind.? ?
> This can produce high-Ni irons with modest Ga and Ge. Nebular?
> condensation can also produce high-Ni iron which then melts to form?
> cores in which high-Ni iron meteorites form.? This process, however,?
> occurs at high temperature where the volatile elements Ga and Ge are?
> depleted.? Finally, you can produce high Ni through fractional?
> crystallization.? Ni prefers the solid phase when a core crystallizes,?
> so early irons are low in Ni and later crystallizing ones are high in?
> Ni.? However, Ga and Ge behave opposite of Ni, so low Ni irons are?
> high in Ga and Ge and high Ni irons are low and Ga and Ge.? ?The?
> published Ga and Ge values are at least a factor of 15 higher than?
> reported for similar iron meteorites.
>
> 5)? The holes exposed in the center of the specimen are not the shape?
> one would expect of weathering, but seem circular.? Circular vugs are?
> commonly produced in slags when gases try to escape.
>
> There was more...including the fact that Indonesia is a nickel-rich?
> locality as well as Tim's conclusion that Lovina was most likely a?
> highly weathered example of a smelted Ni-rich sulfide.
>
> Sales have been suspended and monies are in the process of being?
> returned.? Further testing will be done to confirm Lovina's place of?
> origin and the results will be posted to the list by mid-January.
>
> I think I'll go see the new Clooney film "Up In The Air."? ?Ohhh---and?
> might anyone want an inexpensive 13 kg specimen of Willamette for?
> Christmas?!
>
>
> And how was your day?? ?;-)
>
>
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Received on Wed 09 Dec 2009 07:08:43 AM PST