[meteorite-list] NWA 4530 CO3.05 Specimens

From: Greg Hupe <gmhupe_at_meteoritecentral.com>
Date: Thu, 17 Dec 2009 11:09:03 -0500
Message-ID: <6019E2E357B24A4B9B160FF16B71B435_at_Gregor>

Dear List Members,

I received a few dozen emails asking what is available of NWA 4530. You may
see the only available specimens here:
http://search.ebay.com/_W0QQsassZnaturesvault

Thank you for your interest, I wish the stone was larger to accommodate
everyone!

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

> Hey Greg, Congrats!
>
> Awesome material as usual! What pieces are available, what is your price?
>
> Thanks!
>
> ----- Original Message -----
> From: "Greg Hupe" <gmhupe at htn.net>
> To: <meteorite-list at meteoritecentral.com>
> Sent: Thursday, December 17, 2009 9:32 AM
> Subject: [meteorite-list] Anomalous CO3.05 - NWA 4530
>
>
> Dear List Members,
>
> In light of today's discussion of pristine chondrites, I would like to
> take
> this opportunity to announce Officially-named NWA 4530, an Anomalous
> CO3.05
> Polymict Carbonaceous Chondrite. It is just one of a handful of this
> intensely rare meteorite type.
>
> Here is a quote from the primary researcher who analyzed NWA 4530:
> "NWA 4530 is the most pristine early solar system material I have ever
> seen.
> There are no CO3.05s or CO3.0s or even CO3.1s that are as pristine (W/0)
> as
> NWA 4530... a unique and important meteorite!"
>
> Here is the submitted classification for the Meteoritical Bulletin:
>
> Northwest Africa 4530
> Algeria
>
> Find: September 2006
>
> Carbonaceous chondrite (CO3.05, anomalous)
>
> History: A single 35.9gram stone broken into 5 pieces was purchased by
> Greg
> Hup? from a Moroccan dealer in Tagounite in September 2006.
>
> Physical Characteristics: Very fresh, light to medium gray interior, with
> translucent dark fusion crust with internal bubbles and a prominent
> diamond-shaped reticulated pattern in areas where the crust has flaked
> off.
>
> Petrography (T. Bunch and J. Wittke, NAU; A. Irving, UWS): A polymict,
> unequilibrated meteorite, exhibiting some characteristics consistent with
> other CO3 chondrites (e. g., non-spherical chondrules are most abundant
> and
> are lobate, distended, and highly irregular, some with fine-grained
> accretionary rims). Distinctive chondrule-like objects (designated as CLO)
> are also common and are typically fragmented with miniscule mesostasis.
> Classic chondrule types are few in number and consist mostly of densely
> packed Type I PO and POP with little to no detectable mesostasis. There is
> no apparent correlation of Cr2O3 with FeO in FeO-rich olivine with
> distance
> from core to rim, yet there is a correlation of Cr2O3 with FeO in
> forsteritic cores. Cr-rich olivine rims were not observed. Amoeboid
> olivine
> inclusions are the most common CAI. The fine-grained matrix is
> unrecrystallized with very fine-grained magnetite, sulfides, silica,
> glasses, and silicates. Rare, small cohenite grains were also found.
> Irregular-shaped sulfides are much larger and range in size from 0.02 to
> 0.12 mm. Complex nuggets are of two types: (1) those consisting of
> pentlandite, troilite, and Cr-magnetite, and (2) sulfide-bearing nuggets,
> consisting of a solitary pentlandite grain surrounded by troilite with
> wispy
> oriented inclusions of an unknown sulfide. Magnetite is a common inclusion
> in chondrules, and the composition and distribution of magnetite is
> similar
> to that in CK chondrites. No NiFe metal was observed anywhere. Angular,
> large (up to 2 x 1.5 mm) igneous-textured clasts contain (in vol %):
> forsterite, 79; troilite and pentlandite, 18 and diopside, 3.
>
> Geochemistry: Overall olivine compositions range from, Fa0.03 to Fa72
> (FeO/MnO = 61 - 133, mean is 91). Cr2O3 in FeO-rich olivine fragments has
> a
> range of 0.10 to 0.48 wt % with a peak at 0.34 wt % (N = 84).
> Chondrule-like
> fragments (CLO) have a more overall FeO-rich olivine composition, with
> lower
> Fa range (core Fa = 4; rim Fa =41) and lower Cr2O3 content (0.04 - 0.31,
> mean = 0.18). Chromian spinel, Cr/(Cr+Al) = 0.24 -0.34. Unknown sulfide is
> (in wt. %): Fe, 67.5 and S, 33.2. Cr-magnetite contains 0.47 - 3.1 wt %
> Cr2O3 with minor amounts of MgO, Al2O3, P2O5, CaO and NiO. Unzoned
> igneous-textured clast olivine is Fa2.7 (FeO/MnO = 31) and diopside is
> Fs1.2Wo39. Average matrix analysis (partial, N= 27) by defocused beam
> microanalysis is (in wt %): Na2O = 0.81; K2O = 0.25; S = 2.48; P2O5 =
> 0.44;
> Cr2O3 = 0.45; NiO = 0.45; S/Si = 0.19; Na/Al = 0.31. Oxygen isotopes (D.
> Rumble, CIW): analysis of acid-washed material by laser fluorination gave
> d18O = -4.228; d17O = -7.052; D17O = -4.829 per mil, consistent with CO
> chondrites.
>
> Classification: Carbonaceous chondrite (CO3.05, anomalous). This stone is
> polymict; most components are consistent with CO3 chondrites, although
> chondrule-like components (CLO) are not common in CO chondrites (from a
> survey of 34 specimens in the NAU repository). NWA 4530 is more highly
> oxidized than most CO chondrites and is devoid of metal. The Cr2O3 content
> in olivine and the matrix composition is consistent with CO3.0 - CO3.05
> (Grossman J. N. and Brearley A. J. (2005) M&PS 40, 87-122). The weathering
> grade is W0/1; there is no evidence of any interior weathering. The shock
> level is S1.
>
> Type specimens: A total of 6.4 g and one polished thin section are on
> deposit at UWS. Mr. Philip Mani is the main mass holder.
>
>
>
> 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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Received on Thu 17 Dec 2009 11:09:03 AM PST