[meteorite-list] Pairing discussion/questions

From: Greg Catterton <star_wars_collector_at_meteoritecentral.com>
Date: Mon, 18 Jan 2010 10:01:40 -0800 (PST)
Message-ID: <687904.79309.qm_at_web46405.mail.sp1.yahoo.com>

As always, Jeff offers great insight to this, I highly value his comments.
That is my main point, many stones such as the Martian you mention, being well known pairs could be served better to share a same number rather then many spread around - this would as I said present a problem to dealers and collectors who would then got from having the "main mass" or only stone to just having another one of the lot. Big monetary value is also at stake here. A Martian main mass sells for considerable amount more per gram then a sample from it.

When NWA 5480 was announced, it seems right away more of it came out of morocco for a good amount less per gram. Perhaps its common for them (in Morocco) to hold back on some to sell as what the others were tested as? This could lead to more pairings?

Its just my opinion that we as a community could do much more to make the current system more clear and accurate when it comes to pairing stones.
Surely there is an amount of scientific leeway for variations of readings from type sample to type sample, could this not be applied to pairing?

I am glad to see this getting some discussion as I am sure many will learn valuable information from this. I also think buyers would also like to feel they are better informed as to pairings or potential pairings when making a purchase as this does seem to be a complicated area.


Greg C.





--- On Mon, 1/18/10, Zelimir Gabelica <Zelimir.Gabelica at uha.fr> wrote:

> From: Zelimir Gabelica <Zelimir.Gabelica at uha.fr>
> Subject: Re: [meteorite-list] Pairing discussion/questions
> To: "Greg Catterton" <star_wars_collector at yahoo.com>, meteorite-list at meteoritecentral.com
> Date: Monday, January 18, 2010, 12:46 PM
> Hi Greg,
>
> This might be a typical question for Jeff Grossman.
>
> I am also continuously puzzled by the abundance of paired
> meteorites (thus those that are officially recognized as
> such).
>
> Let's suppose that once one (or a few) meteorite(s) are
> selected from an important lot (as found) and sold to
> someone, this someone (scientist, collector....) would
> envisage its classification.
> And the same will possibly happen with the other meteorites
> from the same lot.
> As a result, there will be as many different NWA numbers,
> as independent classifications (of the - probably- same
> meteorite).
> As most of these classifications probably won't be
> concerted, there will not be pairings reported and we will
> end up with as many different meteorites, most probably of
> the same type, that will never be suspected being paired.
>
> If a pairing is suspected, I believe this results from
> "concerted" analyses (of either meteorites stemming from the
> same lot and analyzed by different groups, or of the same
> meteorites provided by different finders (buyers....)
> brought for analysis to the same group).
>
> This even complicates further if there are more than one
> such "lot" found (meteorite shower spread throughout a large
> strewnfield).
>
> In case of such "concerted" analyzes, I guess that the labs
> will still give a different NWA number to each meteorite (or
> group of meteorites from the same lot) analyzed, because one
> is never sure that 2 meteorites supposed to come from the
> same lot are at 100% the same.
> If pairing is reported, then most of the time (not always)
> it is mentioned in the Met. Bulls.
> But because all analyzes were done independently, each
> analyzed meteorite (or group of meteorites from the same
> verified lot) will receive its own NWA number.
>
> Here I realize that, at that stage, it is very difficult to
> decide to only retain as official the first NWA number
> attributed chronologically and to cancel all the next NWA
> numbers.
>
> I for one am just happy when pairings are reported. This is
> often the case for "important" types such as the
> planetaries.
> But for the "common" H6's or L5's, I believe this is very
> seldom done.
>
> So far, regarding my collection catalogue, here is what I
> mention (for my NWA 4857 sample taken as an example), just
> to have an idea of the total mass of that meteorite
> evaluated so far.
>
> NWA 4857 (Algeria, Shergottite enr maf),? 0.928 g in
> collection;? tkw:1 at 24 g:
>
> ....Paired with NWA 2975 (70.1 g), NWA 2986 (170? g),
> NWA 2987 (82 g), NWA 4766 (225 g), NWA 4783 (120 g), NWA
> 4864 (94 g), NWA 4878 (130 g), NWA 4880 (81.6 g), NWA 4930
> (117.5 g), NWA 5140 (7.5 g), NWA 5214 (50.7 g), NWA 5219 (60
> g), NWA5313 (5.3 g) and NWA 5366 (39.6 g).
> Cumulated tkw: 1273.3 g (as per Jan. 2010)
>
> I know that this neither sheds more light to the problem,
> nor answers your concerns.
> Hopefully someone can add more to the issue.
>
> My best,
>
> Zelimir
>
>
> At 17:09 18/01/2010, Greg Catterton wrote:
> > I have often wondered and after some discussion with
> others I wanted to get the community feeling on the issue of
> pairings.
> >
> > If a meteorite say NWA 1877 for example is out there
> and more is recovered and verified to be the same material
> from the same strewnfield, should the new material share the
> NWA number and the TKW be updated?
> > I have noticed many pairings with NWA 1877 and many
> other meteorites.
> > Same material with different numbers and TKWs listed.
> >
> > Would it not be in the best interest to have all the
> paired samples share on number? This would surely cut the
> amount of NWA material by 1000 or more.
> > Why is this not done?
> >
> > What is the process for pairing material to share the
> NWA number?
> > Is it up to the dealer or the person who did testing?
> >
> > What affect would it have on value if something with a
> listed TKW of 200g suddenly was paired with the 3 other
> numbers assigned to the same material and the TKW was pushed
> to 1kg or more?
> > Surely it would decrease as supply grew. Is this a
> concern for some?
> >
> > I am trying to better understand the politics/red tape
> that goes with this area.
> >
> > Thanks, hope everyone is doing well.
> >
> > Greg C.
> >
> >
> >
> >
> >
> >
> >
> >
> > ______________________________________________
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> > http://six.pairlist.net/mailman/listinfo/meteorite-list
>
> Prof. Zelimir Gabelica
> Universit? de Haute Alsace
> ENSCMu, Lab. GSEC,
> 3, Rue A. Werner,
> F-68093 Mulhouse Cedex, France
> Tel: +33 (0)3 89 33 68 94
> Fax: +33 (0)3 89 33 68 15
>


      
Received on Mon 18 Jan 2010 01:01:40 PM PST