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Northwest Africa 8642
Basic information Name: Northwest Africa 8642
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 8642
Observed fall: No
Year found: 2002
Country: (Northwest Africa)
Mass:help 52 g
Meteoritical Bulletin:  MB 103  (2014)  L6
Recommended:  L6    [explanation]

This is 1 of 12924 approved meteorites (plus 11 unapproved names) classified as L6.   [show all]
Search for other: L chondrites, L chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 15 Nov 2014
Writeup from MB 103:

Northwest Africa 8642 (NWA 8642)

(Northwest Africa)

Purchased: 2002 Feb

Classification: Ordinary chondrite (L6)

History: Purchased February 2002 at the Gem and Mineral show in Tucson by Edwin Thompson from a Moroccan trader. Donated to Cascadia on May 24, 2002.

Physical characteristics: Faceted specimen is covered with a slightly abraded fusion coating; metal is visible on projecting surfaces.

Petrography: (K. Farley, A. Ruzicka, Cascadia) Granoblastic textured rock with poorly defined chondrules were found in thin section. Few chondrules were distinct enough for their sizes to be measured. Among these, chondrule diameter ranged up to ~600 μm. Roughly 15% of the metal has been weathered.

Geochemistry: Olivine (Fa26.5±0.3, N=8), low-Ca pyroxene (Fs21.7±0.1, Wo2.3±0.1En75.9±0.09, N=10), feldspar (Ab82.5±0.4Or6.0±0.4An11.4±0.1, N=7).

Classification: L6 chondrite based on mineral chemistry and texture. Chondrules are very well-integrated with the matrix.

Specimens: Cascadia holds the entire sample which includes 48.6 g, 1 polished thin section, and 1 stub.

Data from:
  Table 0
  Line 0:
Place of purchase:Tucson, Arizona
Date:P 2002 Feb
Mass (g):52
Shock stage:S3
Weathering grade:W1
Fayalite (mol%):26.5±0.3
Ferrosilite (mol%):21.7±0.1
Wollastonite (mol%):2.3±0.1
Classifier:K. Farley and A. Ruzicka\, Cascadia
Type spec mass (g):48.6
Type spec location:Cascadia
Main mass:Cascadia
Comments:Lab number CML 0023; submitted by A. Ruzicka
   and collections
Cascadia: Cascadia Meteorite Laboratory, Portland State University, Department of Geology, Room 17 Cramer Hall, 1721 SW Broadway, Portland, OR 97201, United States; Website (institutional address; updated 28 Oct 2011)
Thompson: Edwin Thompson, 5150 Dawn St., Lake Oswego, OR 97035, United States (private address)
References: Published in Meteoritical Bulletin, no. 103, MAPS 52, 1014, May 2017, http://onlinelibrary.wiley.com/doi/10.1111/maps.12888/full
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     This is 1 of 9806 approved meteorites from (Northwest Africa) (plus 1855 unapproved names)

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