[meteorite-list] Matteo's Challenge Answered(was India #2)

From: Steve Schoner <steve_schoner_at_meteoritecentral.com>
Date: Thu Apr 22 10:28:25 2004
Message-ID: <20031011224716.91432.qmail_at_web12701.mail.yahoo.com>

Mark,

Do you have XRD, XRF, ion microprobes, scanning
electron microscopes?
  
Do you know of anyone that would take the time to use
these to authenticate large specimens or a speck just
to satisfy my whims?

I don't?

And currently I do not have the cash to buy such
devices to test significant meteorites, let alone
specks.

The problem now is getting ANY meteorite, other than
the ultra rares ones classified by any institution
with the staff and budget for such equipment. They
don't have time to examine our specks to determine
whether they are what the seller says that they are.
And even then, most of the institutions that do tests
on rare meteorites want portions of it for their
collections and research.

But you are right, it is wise to know your seller.
Know that they are selling authentic meteorites.
Specks or larger. But for the common collector a
large specimen has a much greater chance of being
authenticated than a speck in a box that takes
microprobe analysis.

I throw my dust away. It is dust.

Rare ones I don't cut, or tamper with just to break
them down to smaller units to sell as specks.

I have always abhored specks. I hate them. It's a
poor way to collect a meteorite just to fill a hole in
a collection. That is my "opinion" and if others in
IMCA or here disagree, fine with me. Opinions are
just opinions. To each his own, and this is my own.

But one thing is sure I will not go out of my way to
buy or sell such specks. The only case where I did so
was Tagish Lake, but there was not at the time
anything much larger than specks anyway.

A 1 to 2 gram fusion crusted sample would have fit my
collection very nicely, but that was not meant to be.

As for that 2mm Chassigny speck that I purchased from
Steve Arnold, that was professionally mounted and 30
microns thin on a slide. I can show that to people
that find it hard to believe that it fell to earth
from Mars.

"How do you know that that tiny speck is what you say
it is?" they ask me. I don't say I bought it from a
legit meteorite dealer. And I don't have to go into
charts or complicated analysis to prove it that it is
what I say it is either. They will still doubt that
anyway. All have to do is go to my microscope, set up
a polorizing viewer and the slide and say, "Look, see
that dark area in the middle of those crystals, that
is glass produced from other minerals as the rock was
ejected off of Mars. Only Martian meteorites and some
moon rocks have that kind of glass. Now examine the
crystals in this dunite; see how fractured they are?
This is also the result of being accellerated to
ejection velocity in a matter of seconds. Using this
kind of microscope, and other more complicated devices
reveal the true nature of even a small chip such as
this..."

With proper interpretation of this tiny sample,
volumes of information can be spoken. Not in esoteric
charts, or a certificate of authenticity from an IMCA
member, but things I can say that can astound, rather
than a tiny speck in a box that has no meaning, nor
can it be authenticated other than that it was bought
from a member of IMCA.

Between us, as fellow collectors, maybe that is fine,
but I am thinking of those new collectors that might
be much more impressed with a slide of such a speck
and the means and ability to really appreciate it.

To me, it is a matter of interpreting our collecions
to a wider audience.

In collecting meteorites, that means everything to me.

Steve Schoner/ams


--- Mark Ferguson <mafer_at_imagineopals.com> wrote:
>
> Hi Steve and List
>
> Steve, I am surely not trying to start an arguement,
> and all people on the
> list respect your opinions, but I would like to
> address and question your
> comments.
>
> > How do you know, other than the reputation of the
> > seller behind it?
> Isn't this exactly what the IMCA is trying to
> establish, authenticity of
> meteorites sold and traded and the reputation of its
> members?
>
> > It is not just an issue with Matteo, but ANY one
> that
> > sells such specks.
> So, if someone cuts a specimen for whatever reason,
> the crumbs from cutting
> should be tossed because you don't feel they can be
> authenticated to your
> satisfaction. The fact that the person cutting it
> and selling the crumbs
> makes no difference to you because that person isn't
> trustworthy and has no
> reputation.
>
> > To determine the authenticy of such one would have
> to
> > destroy the specimen.
> I think this is not the case any longer with the ion
> probe, but then, I'm
> not a scientist, I just have graduated with my
> undergrad degree. I do know,
> personally, that non-destructive testing can be done
> on larger pieces in XRF
> as long as a relatively flat surface is available
> and that non destructive
> analysis by XRD is possible using a few grains and
> vasiline, and these tests
> provide a fair representation of the results
> obtained using the destructive
> tests, and that they are using an ion probe to
> analyse extremely small
> particles of cosmic dust, again, non-destrucively I
> believe, but they don't
> elaborate on technics, they just publish data and
> pictures.
>
> > And even then, questions might remain.
> This is true, but it also used to be that
> measurements between mass
> spectrometers on the same material would result in
> differing values. This
> was a fact at least until the 1980's and may still
> hold to some extent that
> no two machines will yield the same results. So,
> what are you saying then?
> That unless an analysis is done on a machine, you
> won't believe it? So,
> then, maybe you can explain NWA 869 and UCLA's
> attempts to classify it, and
> how you would deal with such inconclusiveness.
>
> > So, my prefrence is that I will not buy any such
> > specks and if I do only in the form of legit thin
> > sections so that the minerology of such can be
> > confirmed via optical and or microprobe means.
>
> So, thats your choice and you have the means to
> purchase what I cannot.
> So, I have a collection of specks that I believe are
> what the sellers says
> they are. And I sell the extra to fund my
> collection. I have no other means
> to purchase these exotic and hard to get meteorites.
>
> What Matteo does is his, and those that deal with
> him, business. Don't
> impose his practices upon others for it implies that
> if one meteorite
> dealer/collector does something, then all must do
> that. And I'm sure that
> your not saying that because Matteo does some
> things, and people have issue
> with him over it, that all dealers or collectors are
> the same way. But, it
> sure sounds that way.
> >
> > Steve Schoner/ams
> >
> >
> Mark
>
>
>
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>
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Received on Sat 11 Oct 2003 06:47:16 PM PDT