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Northwest Africa 7991
Basic information Name: Northwest Africa 7991
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 7991
Observed fall: No
Year found: 2010
Country: (Northwest Africa)
Mass:help 48 g
Classification
  history:
Meteoritical Bulletin:  MB 102  (2013)  Diogenite
Recommended:  Diogenite    [explanation]

This is 1 of 455 approved meteorites classified as Diogenite.   [show all]
Search for other: Achondrites, Diogenites, and HED achondrites
Comments: Approved 14 Nov 2013
Writeuphelp
Writeup from MB 102:

Northwest Africa 7991 (NWA 7991)

(Northwest Africa)

Purchased: 2010

Classification: HED achondrite (Diogenite)

History: Purchased by Terry Boswell in 2010 from a dealer in Erfoud, Morocco.

Petrography: (A. Irving and S. Kuehner, UWS) Medium grained with a metamorphic texture featuring triple grain junctions. Composed predominantly of orthopyroxene with accessory olivine, anorthitic plagioclase, chromite, Ni-poor metal and troilite.

Geochemistry: Orthopyroxene (Fs25.2-25.3Wo3.4-3.8; FeO/MnO = 28-31), olivine (Fa31.1-32.1; FeO/MnO = 50-52).

Specimens: 9.6 g and one polished thin section are at UWB. The remainder is held by Mr. T. Boswell.

Data from:
  MB102
  Table 0
  Line 0:
Place of purchase:Erfoud
Date:P 2010
Mass (g):48
Pieces:1
Class:Diogenite
Shock stage:low
Weathering grade:low
Fayalite (mol%):31.1-32.1
Ferrosilite (mol%):25.2-25.3
Wollastonite (mol%):3.4-3.8
Classifier:A. Irving and S. Kuehner, UWS
Type spec mass (g):9.6
Type spec location:UWB
Main mass:T. Boswell
Comments:TB13-3; 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. 102, MAPS 50, 1662, September 2015
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7655 approved meteorites from (Northwest Africa) (plus 1972 unapproved names)

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