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Northwest Africa 12942
Basic information Name: Northwest Africa 12942
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12942
Observed fall: No
Year found: 2014
Country: Morocco
Mass:help 32.7 g
Recommended:  Eucrite    [explanation]

This is 1 of 569 approved meteorites (plus 1 unapproved name) classified as Eucrite.   [show all]
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 2 May 2020
Writeup from MB 109:

Northwest Africa 12942 (NWA 12942)


Purchased: 2014

Classification: HED achondrite (Eucrite)

History: Purchased from A. Aaronson in 2014 at the Tucson Gem and Mineral Show, who provided origin of sample as being from Morocco. Catalogued in the Royal Ontario Museum collection as LM58152

Physical characteristics: The meteorite has a well-preserved, dark fusion crust, with very minor weathering. Interior of the meteorite intact, uniform and pale gray, with visible thin, black veins and very fine-grained texture.

Petrography: Breccia composed almost entirely of crystal fragments set in a finely comminuted matrix. Crystal fragments range from 60 by 70 μm to 1200 by 600 μm. One gabrroic textured clast, measuring 0.5 by 0.4 cm, is present. Shock state is high as evidenced by strong mosaicism and fracturing of mineral grains.

Geochemistry: Mineral composition and geochemistry: Plagioclase composition: An88.38±3.21Or0.09±0.03 (n=11). Low Ca-pyroxene composition: Fs42.98±14.37Wo6.39±4.74 and FeO/MnO = 30.92±1.10 (n =20). High Ca-pyroxene composition: Fs31.81±1.48Wo28.47±9.97. and FeO/MnO = 30.97±0.71 (n=3).

Classification: (K. Tait, ROM) Texture and compositions suggest the sample is a polymict eucrite breccia.

Data from:
  Table 0
  Line 0:
Place of purchase:Tucson Gem and Mineral Show
Date:P 2014
Mass (g):32.65
Shock stage:high
Weathering grade:low
Ferrosilite (mol%):42.98±14.37; 31.81±1.48
Wollastonite (mol%):6.39±4.74; 28.47±9.97
Classifier:K. Tait, I. Nicklin, ROM
Type spec mass (g):6.53
Type spec location:ROM
Main mass:Dr. David Gregory
Comments:Submitted by V. Di Cecco, ROM
   and collections
ROM: Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2C6, Canada (institutional address; updated 18 Oct 2011)
Aaronson: Sahara Overland Ltd., Harhora, Temara, 12000, Morocco (private address; updated 3 Jan 2010)
References: Published in Meteoritical Bulletin, no. 109, in preparation (2020)
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     This is 1 of 1932 approved meteorites from Morocco (plus 27 unapproved names) (plus 1 impact crater)

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