Zelimir brings up one more case that I didn't cover... when two names
are given to the same physical stone. If the NomCom learns of this and
can be sure that this is what happened, they can abolish one of the names.
jeff
On 2010-01-18 12:46 PM, Zelimir Gabelica wrote:
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...@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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Prof. Zelimir Gabelica
Université 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
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--
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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