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Northwest Africa 6431
Basic information Name: Northwest Africa 6431
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 6431
Observed fall: No
Year found: 2009
Country: (Northwest Africa)
Mass:help 891 g
Recommended:  LL(L)3    [explanation]

This is 1 of 24 approved meteorites classified as LL(L)3.   [show all]
Search for other: LL chondrites, LL chondrites (type 3), Ordinary chondrites, and Ordinary chondrites (type 3)
Comments: Approved 2 Aug 2020
Writeup from MB 109:

Northwest Africa 6431 (NWA 6431)

(Northwest Africa)

Purchased: 2009 Feb

Classification: Ordinary chondrite (LL(L)3)

History: Purchased by Blaine Reed in February 2009 from a Moroccan dealer at the Tucson Gem and Mineral Show.

Petrography: (A. Irving and S. Kuehner, UWS; P. Carpenter, WUSL) Closely packed, well-formed chondrules (apparent diameter 910±550 µm, N = 23) are set in a sparse matrix (opaque in thin section) containing chromite, stained kamacite and troilite.

Geochemistry: Olivine (Fa20.4±15.6, range Fa0.9-44.8, N = 6; Cr2O3 in ferroan olivine = 0.02-0.52 wt.%, mean 0.12±0.14 wt.%, N = 11), orthopyroxene (Fs14.9±8.6Wo1.4±0.6, range Fs1.8-21.6Wo0.6-2.0, N = 5), subcalcic augite (Fs26.4Wo30.5), augite (Fs19.9±2.5Wo39.3±0.4, N = 2). Magnetic susceptibility log χ (× 10-9 m3/kg) = 4.47.

Classification: Ordinary chondrite (LL(L)3).

Specimens: 22.7 g plus one polished thin section at PSF; main mass with Mr. B. Reed.

Data from:
  Table 0
  Line 0:
Place of purchase:Tucson
Date:P 2009 Feb
Mass (g):891
Shock stage:S2
Weathering grade:W1
Fayalite (mol%):0.9-44.3
Ferrosilite (mol%):1.8-19.7
Wollastonite (mol%):1.4-0.9
Magnetic suscept.:4.47
Classifier:A. Irving and S. Kuehner, UWS
Type spec mass (g):22.7
Type spec location:PSF
Main mass:B. Reed
Comments:Work name 21853; submitted by A. Irving
   and collections
PSF: Planetary Studies Foundation,10 Winterwood Lane, Unit B, Galena, Illinois 61036-9283, United States; Website (institutional address; updated 1 Dec 2011)
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)
Reed: Blaine Reed, P.O. Box 1141, Delta, CO 81416, United States; Website (private address)
References: Published in Meteoritical Bulletin, no. 109, in preparation (2020)
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     This is 1 of 9429 approved meteorites from (Northwest Africa) (plus 1876 unapproved names)

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