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 Hupé 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 Hupé (GHupé).
Enjoy!
Best regards,
Greg
====================
Greg Hupe
The Hupe Collection
NaturesVault (eBay)
[email protected]
www.LunarRock.com
IMCA 3163
====================
Click here for my current eBay auctions:
http://search.ebay.com/_W0QQsassZnaturesvault
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