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Northwest Africa 5691
Basic information Name: Northwest Africa 5691
     This is NOT an official name: Discredited meteorite.
Abbreviation: NWA 5691
Observed fall: No
Year found: 2009
Country: Morocco
Mass:help 259 g
Classification
  history:
Meteoritical Bulletin:  MB 98  (2010)  Eucrite
Recommended:  Eucrite    [explanation]

Comments: Entered 14 May 2010
Revised 6 May 2019: This is the same meteorite as NWA 5961
Writeuphelp
Writeup from MB online:

Northwest Africa 5691 (NWA 5691)

Morocco

Found: May 2009

Classification: HED achondrite (Eucrite)

History: A stone found near Zag, Morocco, in May 2009 was purchased by Ali and Mohammed Hmani.

Physical characteristics: A single 259 g orange-brown stone partially covered with remnant dark brown fusion crust.

Petrography: (A. Irving and S. Kuehner, UWS): Ophitic-textured assemblage of calcic plagioclase laths and exsolved pigeonite blades accompanied by relatively large grains of silica polymorph, chromite (of variable Ti content), ilmenite and rare zircon. Exsolved pyroxenes have either coarse lamellae of clinopyroxene in an orthopyroxene host, or lamellae of orthopyroxene in a clinopyroxene host. Plagioclase contains abundant microscopic blebs of exsolved orthopyroxene.

Geochemistry: Orthopyroxene (Fs59.1-59.6Wo4.6-5.1, FeO/MnO = 29.7-31.6), clinopyroxene (Fs29.1-29.3Wo40.3-40.7, FeO/MnO = 31.3-32.7), plagioclase (An88.2-89.7Or0.7). Oxygen Isotopes (D. Rumble, CIW): acid-washed material analyzed by laser fluorination gave, respectively δ18O = 3.63, 3.58; δ17O = 1.66, 1.63; Δ17O = -0.251, -0.253 per mil.

Classification: Achondrite (basaltic eucrite).

Specimens: A total of 22 g of type material, two polished thin sections and a polished mount are on deposit at UWS. The remaining material is held by an anonymous collector.

Data from:
  MB98
  Table 1
  Line 32:
Date:May 2009
Mass (g):259
Pieces:1
Class:Eucrite
Ferrosilite (mol%):59.1-59.6
Wollastonite (mol%):4.6-5.1
Classifier:A. Irving, S. Kuehner, UWS
Type spec mass (g):22
Type spec location:UWS
Main mass:Anon
Comments:Submitted by Irving
Plots: O isotopes:  
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)
CIW: Carnegie Insitution Washington, Geophysical Laboratory, 5251 Broad Branch Rd., NW, Washington DC 20015, United States (institutional address)
Hmani: A. Hmani Moroccan Imports, 13 rue Jules Hardouin Mansart, 92600 Asnières, France (private address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 98, MAPS 45, 1530-1551 (2010)
Find references in NASA ADS:
Find references in Google Scholar:
Geography:

Morocco
Coordinates:Unknown.

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