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Northwest Africa 7325
Basic information Name: Northwest Africa 7325
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 7325
Observed fall: No
Year found: 2012
Country: (Northwest Africa)
Mass:help 345 g
Classification
  history:
Recommended:  Achondrite-ung    [explanation]

This is 1 of 67 approved meteorites classified as Achondrite-ung.   [show all]
Search for other: Achondrites, Ungrouped achondrites
Comments: Approved 18 Dec 2012
Writeuphelp
Writeup from MB 101:

Northwest Africa 7325 (NWA 7325)

(Northwest Africa)

Purchased: 2012 Apr

Classification: Ungrouped achondrite

History: Purchased by Stefan Ralew in April 2012 from a dealer in Erfoud, Morocco. The material was found reportedly in southern Morocco in early 2012.

Physical characteristics: A group of 35 very fresh, dark greenish stones (total 345 g), several of which have partial remnant chartreuse-colored fusion crust. This material is notable for the characteristic "frosty" luster of the plagioclase and bright green color of the clinopyroxene.

Petrography: (A. Irving and S. Kuehner, UWS): The studied specimen has an overall plutonic igneous (possibly cumulate) texture. It is a medium-grained aggregate of Al-Cr-bearing diopside, calcic plagioclase and lobate (possibly resorbed) grains of forsterite, with accessory Cr-bearing iron sulfide (probably troilite), very sparse ferrochromite, kamacite and taenite, and rare eskolaite (associated with Cr-Fe sulfide). In thin section the untwinned plagioclase is birefringent, but the levels of birefringence are less than normal and variable on a fine scale (suggesting the existence of compositional and/or structural microdomains); there also are sparse vesicles (suggesting at least partial melting). The pyroxene exhibits at least two sets of polysynthetic twin lamellae, which resemble those produced by moderately high shock.

Geochemistry: Clinopyroxene (Fs1.1-2.6 Wo45.1-44.5, FeO/MnO = 12-21, Al2O3 = 2.6-2.8 wt.%, Cr2O3 = 1.0 wt.%), plagioclase (An88.1-89.2Or0.0), olivine (Fa2.7-2.8, FeO/MnO = 30-36, CaO = 0.27-0.32 wt.%, Cr2O3 = 0.32-0.35 wt.%). Bulk composition (G. Chen, UAb): analyses of representative bulk wire-saw cutting dust by ICP-MS gave: (in ppm) La 0.15, Ce 0.34, Nd 0.16, Sm 0.05, Eu 0.58, Gd 0.05, Hf 0.44, Th 0.27. Oxygen isotopes (K. Zeigler, UNM): laser fluorination analyses of acid-washed subsamples gave, respectively δ17O = 3.214, 3.670, 3.249; δ18O = 7.566, 8.204, 7.957; Δ17O = -0.781, -0.662, -0.952 per mil [for TFL slope of 0.528].

Classification: Achondrite (ungrouped). The combination of highly magnesian mafic silicates and highly calcic plagioclase with chromium-bearing sulfides is unique among achondrites, and the specimen is highly depleted in most trace elements.

Specimens: A total of 21 g of type material and one polished thin section are on deposit at UWB. The remaining material is held by Ralew.

Data from:
  MB101
  Table 0
  Line 0:
Place of purchase:Erfoud
Date:P 2012 Apr
Mass (g):345
Pieces:35
Class:Achondrite-ung
Shock stage:medium
Weathering grade:low
Fayalite (mol%):2.7-6.0
Ferrosilite (mol%):2.6
Wollastonite (mol%):44.5
Classifier:A. Irving and S. Kuehner, UWS
Type spec mass (g):21
Type spec location:UWB
Main mass:S. Ralew
Comments:Submitted by A. Irving
Plots: O isotopes:  
Institutions
   and collections
UNM: Institute of Meteoritics MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 USA, United States; Website (institutional address; updated 12 Feb 2015)
UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012)
UAb: 1-26 Earth Sciences Building, University of Alberta, Edmonton, AB, T6G 2E3, Canada, Canada; Website (institutional address; updated 17 Oct 2011)
UWB: University of Washington, Box 353010 Seattle, WA 98195, United States (institutional address; updated 27 Jul 2012)
Ralew: Stefan Ralew, Kunibertstraße 29, 12524 Berlin, Germany; Website (private address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 101, MAPS 47, in preparation (2013)
Find references in NASA ADS:
Find references in Google Scholar:
Photos:
CreditPhotos
Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
Denis gourgues         
Dominik Stoeckli   
Francois Pacaud   
Gregor H.   
Piotr gural100   
steve sutton   
Steve Witt   
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 4784 approved meteorites from (Northwest Africa) (plus 2276 unapproved names)

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