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Northwest Africa 11774
Basic information Name: Northwest Africa 11774
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 11774
Observed fall: No
Year found: 2018
Country: Mauritania
Mass:help 439 g
Classification
  history:
Recommended:  Mesosiderite    [explanation]

This is 1 of 175 approved meteorites classified as Mesosiderite.   [show all]
Search for other: Mesosiderites, Metal-rich meteorites
Comments: Approved 12 May 2018
Writeuphelp
Writeup from MB 107:

Northwest Africa 11774 (NWA 11774)

Mauritania

Purchased: 2018 Jan

Classification: Mesosiderite

History: Found near Ain Ben Tili, Mauritania, in December 2017 and purchased by Bob Falls in January 2018 from a Moroccan dealer.

Physical characteristics: A single metal-rich mass (439.2 g) with a weathered exterior. The fresh interior consists mainly of metal with ~10 vol.% interstitial silicate-rich material.

Petrography: (A. Irving and S. Kuehner, UWS) Composed predominantly of granular kamacite (containing small, irregularly-shaped grains of taenite and rare schreibersite) together with interstitial regions containing calcic plagioclase, orthopyroxene, silica polymorph, chromite, merrillite, ilmenite and troilite.

Geochemistry: Orthopyroxene (Fs30.3-31.7Wo2.9-3.8, FeO/MnO = 18-19, N = 3), plagioclase (An85.3-86.9Or0.5-0.2, N = 2).

Classification: Mesosiderite. This specimen has close textural and mineralogical similarities to the metal-rich nodules in Bondoc, and is unusual because of its very high metal/silicate ratio relative to typical examples.

Specimens: 24.1 g in the form of a polished slice at UWB; remainder with Mr. R. Falls.

Data from:
  MB107
  Table 0
  Line 0:
Place of purchase:Zagora
Date:P 2018 Jan
Mass (g):439.2
Pieces:1
Class:Mesosiderite
Shock stage:low
Weathering grade:low
Ferrosilite (mol%):30.3-33.5
Wollastonite (mol%):3.6-5.3
Classifier:A. Irving & S. Kuehner
Type spec mass (g):24.1
Type spec location:UWB
Main mass:R. Falls
Comments:Work name BF18-22; 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)
UWB: University of Washington, Box 353010 Seattle, WA 98195, United States (institutional address; updated 27 Jul 2012)
Catalogs:
References: Published in Meteoritical Bulletin, no. 107, in preparation (2018)
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Geography:

Mauritania
Coordinates:Unknown.

Statistics:
     This is 1 of 88 approved meteorites from Mauritania (plus 2 impact craters)

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