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Northwest Africa 12758
Basic information Name: Northwest Africa 12758
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12758
Observed fall: No
Year found: 2019
Country: Mali
Mass:help 2.4 kg
Classification
  history:
Recommended:  Achondrite-ung    [explanation]

This is 1 of 86 approved meteorites classified as Achondrite-ung.   [show all]
Search for other: Achondrites, Ungrouped achondrites
Comments: Approved 3 Sep 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12758 (NWA 12758)

Mali

Purchased: 2019 Jan

Classification: Ungrouped achondrite

History: Purportedly found in Mali and purchased in Agadir, Morocco, by Aziz Habibi in January 2019.

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Protogranular aggregate (mean grainsize 0.8 mm) of predominantly low-Ca pyroxene (~70 vol.%) and magnesian olivine (~30 vol.%) with accessory Si-bearing kamacite and Cr-bearing troilite. Plagioclase is absent. Minor secondary Fe hydroxides coat grain boundaries.

Geochemistry: Low-Ca pyroxene (Fs5.9-6.0Wo4.7-4.9, FeO/MnO = 20-22, N = 3), olivine (Fa6.5-6.9, FeO/MnO = 29-39, N = 4), metal (Ni = 6.5 wt.%, Si = 1.1 wt.%). Oxygen isotopes (K. Ziegler, UNM); analyses of acid-washed subsamples by laser fluorination gave, respectively, δ17O -1.168, -1.115, -1.099; δ18O 1.422, 1.429, 1.557; Δ17O -1.918, -1.869, -1.921 per mil.

Classification: Achondrite (ungrouped, ultramafic).

Specimens: 22.7 g including one polished thin section at UWB; remainder with A. Habibi.

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Agadir
Date:P 2019 Jan
Mass (g):2400
Pieces:1
Class:Achondrite-ung
Shock stage:low
Weathering grade:low
Fayalite (mol%):6.5-6.9
Ferrosilite (mol%):5.9-6.0
Wollastonite (mol%):4.7-4.9
Classifier:A. Irving, UWS, and P. Carpenter, WUSL
Type spec mass (g):22.7
Type spec location:UWB
Main mass:A. Habibi
Comments:Work name AH 730; 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)
WUSL: Washington Univ., One Brookings Drive, St. Louis, MO 63130, United States (institutional address; updated 17 Oct 2011)
UWB: University of Washington, Box 353010 Seattle, WA 98195, United States (institutional address; updated 27 Jul 2012)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108, in preparation (2019)
Find references in NASA ADS:
Find references in Google Scholar:
Geography:

Mali
Coordinates:Unknown.

Statistics:
     This is 1 of 33 approved meteorites from Mali (plus 1 unapproved name)

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