[meteorite-list] NWA 2918 CO3.0 reclassification AND MostCurrent/Accurate Meteorite Classification

From: Adam Hupe <raremeteorites_at_meteoritecentral.com>
Date: Sat Jul 22 20:37:28 2006
Message-ID: <003b01c6adf0$5da09880$6401a8c0_at_c1720188a>

I was told that the new method which Dr. Grossman proposed was used in
determining a perfect 3.0 by the scientists involved with the study so I
guess this leaves some confusion. The Cr2O3 measurements in olivine was
reported so I will have to go with NAU's results for now. By the way,
David, why are you so jealous that you need to look for fault where none
exists? We have hundreds of classifications under our belt and so do other
dealers. Why is that you only mention pieces we are involved with? We do
not make this stuff up, it is reported in the bulletin. You have been wrong
so many times and not once have you apologized. Instead you persist in
trying to start arguments.

I have lost all respect for you,

Adam





----- Original Message -----
From: "Jeff Grossman" <jgrossman_at_usgs.gov>
To: "Meteorite List" <meteorite-list_at_meteoritecentral.com>
Sent: Saturday, July 22, 2006 5:11 PM
Subject: Re: [meteorite-list] NWA 2918 CO3.0 reclassification AND
MostCurrent/Accurate Meteorite Classification


> Two replies for the price of one:
>
> 1) NWA 2918. An abstract is not peer reviewed, however I'll stand by
> my classification of NWA 2918. It's a very nice meteorite, but more
> metamorphosed than 3.0. There are actually three CO3.0
> chondrites. In addition to ALHA77307, Y-81020 and Colony are both
> 3.0, but Colony is so horribly weathered that it is scarcely worth
mentioning.
>
> 2) What is the most current and accurate classification? Let me
editorialize.
>
> * The Catalogue of Meteorites online database used to be the best,
> but it has simply not been updated frequently enough to keep up with
> current science or new
> meteorites. http://www.nhm.ac.uk/research-curation/projects/metcat/
>
> * MetBase, which is not an online resource, is very current (usually
> within 6 months), but in a few cases the classifications have been
> updated in a less conservative way than I would
> do. http://www.metbase.de/. It is an excellent resource.
>
> * The original Meteoritical Bulletin classifications were simply
> initial evaluations, so they are not to be trusted down the road.
>
> * In the MetBull database, you will find a "recommended"
> classification. These are largely taken from MetBase plus NomCom,
> ANSMET, and NIPR data releases that postdate the latest edition of
> MetBase. However, they are tempered by me. For example, if you look
> up Tagish Lake, MetBase will tell you it's CI2, which was a
> speculative statement in the initial description and a few
> abstracts. The NHM Catalogue database just says C2, which is not
> very helpful. If you read the literature, especially Zolensky's big
> 2002 paper in MAPS, it's pretty clear that a conservative conclusion
> would be C2 ungrouped. So when I think MetBase went too far, as in
> this case, I back it off a bit in the recommendation. In other
> words, I am the editor of this database. You can always see the
> original MetBull, the NHM, and the MetBase classification as well.
> http://tin.er.usgs.gov/meteor/
>
> * The new Encyclopedia of Meteorites is a work in progress. It gets
> a lot of information directly from the MetBull database (in real time
> now!), but it also lists a number of meteorites that are not formally
> named or classified. You take your chances with these, as far as I'm
> concerned. http://www.encyclopedia-of-meteorites.com/login.asp
>
> If there's anything else out there online, I don't know much about
> it. So there you have it.
>
> Jeff
>
> At 07:25 PM 7/22/2006, David Weir wrote:
> >Hello Adam,
> >
> >I just wanted to bring to your attention the new MetSoc abstract
> >written by Jeff Grossman et al. which disputes the initial
> >classification of your CO3.0 NWA 2918, and argues that it's actually
> >a CO3.1. I see that you still have this meteorite for sale on ebay
> >as a CO3.0 and I'm sure you'll want to include this correction in
> >your accompanying description (see below) for the benefit of the
> >potential buyer. Obviously the new stricter standards to which you
> >refer are not the strictest in use. When I bought my two small
> >pieces of this one from you I admit I was speculating that it would
> >hold up as a rare CO3.0 comparable to the only known CO3.0,
> >ALHA77307, especially based on your description, but a CO3.1 is not
> >bad either. The abstract can be viewed here:
> >
> >http://www.lpi.usra.edu/meetings/metsoc2006/pdf/5283.pdf
> >
> >Since this was not published in a peer-reviewed journal perhaps Jeff
> >Grossman is wrong, time will tell. Keep up the great work in finding
> >us new rare material Adam.
> >
> >Regards,
> >
> >David
> >meteoritestudies.com
> >--------------------------------------------
> >BRAND NEW-NWA 2918 Intensely Rare CO3.0 Meteorite .752g
> >
> >.752 gram end cut of Northwest Africa 2918, a CO3.0, S1, W2 Ornans
> >type carbonaceous chondrite found 2005 in the Sahara desert. The
> >perfect 3.0 subtype is exceeding rare among all types of chondrites
> >but is the ultimate rarity among CO type chondrites with only one
> >other non-Antarctic meteorite listed in the Catalog of Meteorites
> >which is named Colony. NWA 2918 was graded using the new stricter
> >standards so it is now the only perfect 3.0 in private hands that I
> >am aware of since Colony was slightly downgraded to a 3.0-3.1 using
> >the same new standards. The only other perfect 3.0 is an Antarctic
> >piece named ALH 77307, which is not available to the public. Only
> >one stone was found and it weighed only 237 grams making it an
> >intensely rare specimen.
> >
> >______________________________________________
> >Meteorite-list mailing list
> >Meteorite-list_at_meteoritecentral.com
> >http://six.pairlist.net/mailman/listinfo/meteorite-list
>
> Dr. Jeffrey N. Grossman phone: (703) 648-6184
> US Geological Survey fax: (703) 648-6383
> 954 National Center
> Reston, VA 20192, USA
>
>
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Received on Sat 22 Jul 2006 08:33:18 PM PDT