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Northwest Africa 12953
Basic information Name: Northwest Africa 12953
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12953
Observed fall: No
Year found: 2019
Country: Algeria
Mass:help 1939 g
Meteoritical Bulletin:  MB 108  (2020)  Diogenite
Recommended:  Diogenite    [explanation]

This is 1 of 481 approved meteorites classified as Diogenite.   [show all]
Search for other: Achondrites, Diogenites, and HED achondrites
Comments: Approved 7 Nov 2019
Writeup from MB 108:

Northwest Africa 12953 (NWA 12953)


Purchased: 2019 Jun

Classification: HED achondrite (Diogenite)

History: The majority of this material was purchased by Jason Bliss in June 2019 from a dealer in Oregon, who had acquired it from an Algerian source. Later in September 2019 additional amounts of the same material were purchased jointly by Jason Bliss and Topher Spinnato from a Moroccan dealer. Samples form both batches were examined and analyzed.

Physical characteristics: The material (total weight 1939 g) comprises muliple relatively coarse-grained, friable stones (locally stained dull orange-brown with black chromite grains visible).

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Breccia composed predominantly of angular grains of orthopyroxene (exhibiting undulose extinction) plus some polygranular diogenite clasts in a sparse finer-grained matrix. Accessory phases include olivine, clinopyroxene, V-bearing chromite, troilite and iron hydroxides (evidently produced by pervasive terrestrial weathering of primary Ni-free metal).

Geochemistry: Orthopyroxene (Fs23.8-23.9Wo1.7-1.9, FeO/MnO = 25-26, N = 4), olivine (Fa27.1-27.7, FeO/MnO = 43-45, N = 4), clinopyroxene (Fs8.0Wo46.2, FeO/MnO = 20), chromite (V2O3 = 0.5 wt.%).

Classification: Diogenite (breccia, stained by terrestrial weathering).

Specimens: 41.7 g including one polished thin section and one polished mount at UWB; remainder held jointly by Mr. J. Bliss and Mr. T. Spinnato.

Data from:
  Table 0
  Line 0:
Place of purchase:Oregon; Morocco
Date:P 2019 Jun
Mass (g):1939
Shock stage:low
Weathering grade:moderate
Fayalite (mol%):27.1-27.7
Ferrosilite (mol%):23.8-23.9
Wollastonite (mol%):1.7-1.9
Classifier:A. Irving, UWS, and P. Carpenter, WUSL
Type spec mass (g):41.7
Type spec location:UWB
Main mass:J. Bliss/ T. Spinnato
Comments:Work name JB19-2; submitted by A. Irving
   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)
References: Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
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     This is 1 of 1153 approved meteorites from Algeria (plus 27 unapproved names) (plus 4 impact craters)

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