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Northwest Africa 12974
Basic information Name: Northwest Africa 12974
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12974
Observed fall: No
Year found: 2019
Country: (Northwest Africa)
Mass:help 29 g
Classification
  history:
Recommended:  Ureilite-mmict    [explanation]

This is the only approved meteorite classified as Ureilite-mmict.
Search for other: Achondrites, Ureilites
Comments: Approved 23 Dec 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12974 (NWA 12974)

(Northwest Africa)

Purchased: 2019 Sep

Classification: Ureilite-mmict

History: Purchased by Adam Aaronson in Temara, Morocco, in September 2019.

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Breccia composed predominantly of angular grains of zoned olivine and pigeonite with accessory augite, schreibersite, troilite and altered kamacite (as abundant cross-cutting veinlets). No carbon phases were observed. Olivine grains have more ferroan cores and reduced, more magnesian rims. Minor secondary iron chloride and calcium sulfate are associated with altered kamacite.

Geochemistry: Olivine (cores Fa11.7-12.7, N = 4; rims Fa6.5-9.1, N = 4), pigeonite (Fs11.2-11.3Wo9.8-9.6, N = 2), augite (Fs6.8-7.5Wo36.4-35.4, N = 3).

Classification: Ureilite (monomict breccia).

Specimens: 6.2 g including one polished thin section and one polished mount at UWB; remainder with Aaronson.

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Temara
Date:P 2019 Sep
Mass (g):29
Pieces:1
Class:Ureilite-mmict
Shock stage:moderate
Weathering grade:low
Fayalite (mol%):11.7-12.7
Ferrosilite (mol%):11.2-11.3; 7.5-6.8
Wollastonite (mol%):9.6-9.8; 35.4-36.4
Classifier:A. Irving, UWS, and P. Carpenter, WUSL
Type spec mass (g):6.2
Type spec location:UWB
Main mass:A. Aaronson
Comments:Work name M2062; 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)
Aaronson: Sahara Overland Ltd., Harhora, Temara, 12000, Morocco (private address; updated 3 Jan 2010)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108, in preparation (2019)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7354 approved meteorites from (Northwest Africa) (plus 1958 unapproved names)

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