[meteorite-list] My first classification - NWA 6696 (LL3.6)

From: Galactic Stone & Ironworks <meteoritemike_at_meteoritecentral.com>
Date: Fri, 29 Apr 2011 14:28:25 -0400
Message-ID: <BANLkTimzJVmZKhjMq8Z69Z1BHPpJNuDzPQ_at_mail.gmail.com>

Hi Larry, Gary and List,

Here are some photos of NWA 6696 -

http://s268.photobucket.com/albums/jj24/Meteoritethrower/Meteorites/chondrules/

I have a few more on my HD somewhere, but there isn't much to see on
such a small stone. My only regret is that the stone is so small.
The matrix is wall-to-wall chondrules, many of which are surrounded by
a thin rim of metal. This stone just goes to show (as Larry said)
that visual pairings are misleading. I'd seen photos of CR stones
that looked exactly like my specimen. The main reason I submitted it
is because I was confident it was a CR. Then I was pleasantly
surprised by the LL3.6 classification, given the presence of
visually-abundant metal. A large stone like this would produce some
very attractive slices.

Of course, like many chondrule-rich OC's, the look is not improved by
polishing. The chondrules darken and become invisible when polished
(except for a few of the whitish colored ones). So I left one side of
my remaining slice unpolished.

By virtue of numbers, this LL3.6 is more scarce than a CR. There are
115 approved CR meteorites and only 16 LL3.6 stones. It's good to
know that my stone is in good company with Parnallee and is sitting in
a UCLA cabinet where it might contribute to science in some way. :)

Best regards,

MikeG

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On 4/29/11, Larry Atkins <thetoprok at aol.com> wrote:
> Hi Mike, List,
>
> Congrat's on your classification!
>
> The way you described the meteorite as having armored chondrules and
> thinking it was possibly a CR, then finding out it's an LL 3.6 made me
> think of a very similar scenario that has recently played out for me. I
> thought a chondrite I bought in 2008 was possibly a CR as did some
> other list members and it turned out to be an LL 3.8. I'd like to see
> pictures of yours Mike, I wonder if it looks similar. Here's a link to
> pic's of my new classifications, NWA 6581, ( LL 6) and NWA 6582, the LL
> 3.8.
>
> http://s934.photobucket.com/albums/ad190/alienrockfarm/
>
>
> I saw that yours is 1 of only 16 meteorites with that classification,
> so despite its "unassuming" status amongst a pile of lunars and such,
> it's still a rarity!
>
>
> Sincerely,
> Larry Atkins
>
> IMCA # 1941
> Ebay alienrockfarm
>
>
>
> -----Original Message-----
> From: Galactic Stone & Ironworks <meteoritemike at gmail.com>
> To: Meteorite List <meteorite-list at meteoritecentral.com>
> Sent: Fri, Apr 29, 2011 11:41 am
> Subject: [meteorite-list] My first classification - NWA 6696 (LL3.6)
>
>
> Hi List,
>
> Some new meteorites were added to the Met Bulletin today, including
> some new lunars.
>
> Hidden amongst the more exciting lunars is an unassuming LL3.6 - NWA
> 6696.
>
> This small 10g stone came in a batch of unclassified NWA that I
> purchased about 3 years ago. Upon windowing this small stone, I saw
> an adundance of armored chondrules. At first glance, it resembled a
> CR type. I posted some photos to this list, a minor discussion
> ensued, and then the sample went off to the lab to be looked at by Dr.
> Alan Rubin. Of course, it's not worthwhile for anyone to classify
> such a small OC when the 20/20 classification sample would only be 2
> grams. So I offered to reverse the usual 20/20 arrangement - I'd keep
> 2 grams and the lab could keep the 8g "main mass". Now the
> classification is official.
>
> I was hoping to sneak my name into the literature, but alas, I didn't
> get to see my name in lights. LOL
>
> It should be noted, that for collectors, this is going to be one of
> those impossible to acquire NWAs. Given the low TKW and that 80% of
> the mass is sitting at UCLA, that leaves a scant 2g on the collector
> market. A while back, I swapped a small endcut to Greg Catterton and
> I still retain a 1g slice that is polished on one side. If anyone
> wants to make me an insane offer for the remaining 1g slice, I will
> entertain all such offers. ;)
>
>
> >From the write-up :
>
> Northwest Africa 6696 (NWA 6696)
>
> Morocco
>
> Purchased: 2007
>
> Classification: Ordinary chondrite (LL3.6)
>
> Classification: Ordinary chondrite, LL3.7. The olivine Fa distribution
> (Fa24.4?9.1) and low-Ca pyx Fs distribution (Fs12.3?7.1) are
> appreciably more heterogeneous than those of Dhajala (type 3.8),
> indicating a subtype <3.8. The meteorite contains abundant low-Ca
> clinopyroxene with polysynthetic twinnning (indicating type <4) and
> moderately abundant fine-grained matrix material (most consistent with
> type 3.0-3.6). Clear chondrule glass is most abundant in type 3.0-3.5;
> this meteorite lacks clear chondrule glass, implying a subtype >3.5.
> Hence, 3.6 seems the most likely subtype.
>
>
> Best regards,
>
> MikeG
>
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>
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> Galactic Stone & Ironworks - Meteorites & Amber
>
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Received on Fri 29 Apr 2011 02:28:25 PM PDT