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Northwest Africa 12691
Basic information Name: Northwest Africa 12691
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12691
Observed fall: No
Year found: 2017
Country: (Northwest Africa)
Mass:help 103.8 kg
Classification
  history:
Meteoritical Bulletin:  MB 108  (2020)  Lunar (feldsp. breccia)
Recommended:  Lunar (feldsp. breccia)    [explanation]

This is 1 of 276 approved meteorites classified as Lunar (feldsp. breccia).   [show all]
Search for other: Lunar meteorites
Comments: Approved 31 Aug 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12691 (NWA 12691)

(Northwest Africa)

Find: 2017 Jan

Classification: Lunar meteorite (feldspathic breccia)

History: Scores of  specimens (total weight 103.770 kg) were found in January 2017 in Western Sahara or the Western Sahara/Algeria border region, and purchased by Darryl Pitt in February 2017 from a Mauritanian dealer.  The largest specimens weigh 15.555 kg, 15.435 kg, 13.650 kg, 12.480 kg, 8.960 kg and 3.460 kg; nine specimens weigh between 1-4 kg, 31 specimens weigh between 100-500 g, and there are numerous smaller fragments.

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Breccia composed of angular mineral clasts of anorthite, olivine, pigeonite, subcalcic augite, chromite and ilmenite, together with some quench-textured lithic clasts, set in a sparsely vesicular, parly vitreous matrix containing minor troilite, kamacite and taenite.

Geochemistry: Olivine (Fa21.5-47.7, FeO/MnO = 87-102, N = 4), pigeonite (Fs38.5-43.0Wo7.1-5.3, FeO/MnO = 57-58, N = 2), subcalcic augite (Fs38.4Wo24.0, FeO/MnO = 53), plagioclase (An96.7Or0.1).

Classification: Lunar (feldspathic breccia).

Specimens: 20.3 g including four polished endcuts from separate stones at UWB; remainder with DPitt.

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Mauritania
Date:2017 Jan
Mass (g):103770
Pieces:many
Class:Lunar (feldsp. breccia)
Shock stage:low
Weathering grade:low
Fayalite (mol%):21.5-47.7
Ferrosilite (mol%):38.5-43.0
Wollastonite (mol%):7.1-5.3
Classifier:A. Irving, UWS, and P. Carpenter, WUSL
Type spec mass (g):20.3
Type spec location:UWB
Main mass:DPitt
Comments:Work name MVCH 270A; submitted by A. Irving
Institutions
   and collections		 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)
DPitt: Darryl Pitt, 225 West 83rd Street, New York, NY 10024, United States; Website (private address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 8509 approved meteorites from (Northwest Africa) (plus 1899 unapproved names)

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