[meteorite-list] NEW Ungrouped Achondrite - NWA 5297

From: Galactic Stone & Ironworks <meteoritemike_at_meteoritecentral.com>
Date: Thu, 25 Feb 2010 14:37:08 -0500
Message-ID: <e51421551002251137m4d365p88538f5148147a81_at_mail.gmail.com>

Hi Greg and List,

Very unusual and interesting specimen Greg.

One thing that strikes me with some of these ungrouped meteorites (and
even some like Lodranites), is how they superficially resemble a
weathered OC on the outside. I wonder how many of these oddballs I
have overlooked in my shipments of weathered uNWA?

Was there something about the external appearance of this specimen
that caught your attention? How did you decide to have it classified
as opposed to the thousands of other similar-looking stones you have
had? Just curious.

Best regards,

MikeG


On 2/25/10, Greg Hupe <gmhupe at htn.net> wrote:
> Dear List Members,
>
> I would like to announce a new Ungrouped Achondrite, NWA 5297.
>
> NWA 5297 is an Ungrouped Achondrite that was found in Morocco in early 2008.
> A total of nine small dark stones were collected with a combined Total Known
> Weight of just 130 grams. NWA 5297 does not fit in any of the known
> classification types, making it a very unusual meteorite.
>
>
>
> Image of 12.9g main mass:
>
> http://www.lunarrock.com/nwa5297/nwa5297e.jpg
>
>
>
> Image of 2.9g complete slice with large metal grain:
>
> http://www.lunarrock.com/nwa5297/nwa5297f.jpg
>
>
>
> Classification submitted to the Meteoritical Bulletin for NWA 5297:
>
> Northwest Africa 5297
>
> Morocco
>
> Find: March 2008
>
> Achondrite (ungrouped)
>
> History: Found near Alargoug, Morocco in March 2008 and purchased in June
> 2008 by Greg Hup? from a Moroccan dealer.
>
> Physical characteristics: A total of nine dark stones with visible metal and
> a combined weight of 130 g.
>
> Petrography: (A. Irving and S. Kuehner, UWS) This specimen has a
> poikiloblastic metamorphic texture with no chondrules and contains
> relatively abundant (~10 vol. %) Ni-rich metal. The major phases are
> olivine, orthopyroxene, taenite and very sodic plagioclase with minor
> Ni-bearing troilite.
>
> Geochemistry: Olivine (Fa28.6, FeO/MnO = 54.4), plagioclase
> (Ab86.2An9.1Or4.7), taenite (~10 wt.% Ni). Oxygen Isotopes (D. Rumble,
> CIW): replicate analyses of acid-washed silicate material by laser
> fluorination gave, respectively: d18O = 4.830, 5.032; d17O = 3.711, 3.818;
> D17O = 1.171, 1.171 per mil.
>
> Classification: Achondrite (ungrouped). This specimen is a metachondrite
> with an oxygen isotopic composition like those of LL chondrites; however, it
> contains too much metal to be regarded as a product of metamorphism of
> typical LL chondrites, and the olivine composition is outside the range for
> equilibrated LL chondrites.
>
> Specimens: A total of 20 g of sample and one polished thin section are on
> deposit at UWS. The main mass is held by Mr. Greg Hup? (GHup?).
>
> Enjoy!
>
> Best regards,
> Greg
>
> ====================
> Greg Hupe
> The Hupe Collection
> NaturesVault (eBay)
> gmhupe at htn.net
> www.LunarRock.com
> IMCA 3163
> ====================
> Click here for my current eBay auctions:
> http://search.ebay.com/_W0QQsassZnaturesvault
>
>
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-- 
------------------------------------------------------------
Mike Gilmer - Galactic Stone & Ironworks Meteorites
http://www.galactic-stone.com
http://www.facebook.com/galacticstone
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Received on Thu 25 Feb 2010 02:37:08 PM PST