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Northwest Africa 8643
Basic information Name: Northwest Africa 8643
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 8643
Observed fall: No
Year found: 2002
Country: (Northwest Africa)
Mass:help 8 g
Classification
  history:
Meteoritical Bulletin:  MB 103  (2014)  L6
Recommended:  L6    [explanation]

This is 1 of 11485 approved meteorites (plus 6 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
Writeuphelp
Writeup from MB 103:

Northwest Africa 8643 (NWA 8643)

(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: Small medium gray specimen completely lacking fusion crust, with numerous dark grains protruding from surface often surrounded by rust halos.

Petrography: (K. Farley, A. Ruzicka, Cascadia) Thin section reveals granoblastic texture with well-integrated chondrules. Rust staining occurs in clumps around some metal and sulfide grains. Individual chondrules are difficult to distinguish, but the 7 most distinct have a mean chondrule diameter of ~0.45 mm. Roughly 10% of the metal has been weathered.

Geochemistry: Olivine (Fa25.5±0.2, N=20), low-Ca pyroxene (Fs21.5±0.2Wo1.5±0.2En77.0±0.2, N=22), high-Ca pyroxene (Fs7.5±0.8Wo45.5±1.0En47.0±0.3, N=6), feldspar (Ab82.6±1.0Or6.6±0.9An10.8±0.1, N=4).

Classification: L6 chondrite based on mineral chemistry and texture.

Specimens: Cascadia holds the entire sample which includes 6.4 g in two pieces, 1 polished thin section, and 1 butt.

Data from:
  MB103
  Table 0
  Line 0:
Place of purchase:Tucson, Arizona, U.S.A.
Date:P 2002 Feb
Mass (g):8
Pieces:1
Class:L6
Shock stage:S3
Weathering grade:W1
Fayalite (mol%):25.5±0.2
Ferrosilite (mol%):21.5±0.2
Wollastonite (mol%):1.5±0.2
Classifier:K. Farley and A. Ruzicka, Cascadia
Type spec mass (g):6.4
Type spec location:Cascadia
Main mass:Cascadia
Comments:Lab number CML 0024; submitted by A. Ruzicka
Institutions
   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)
Catalogs:
References: Published in Meteoritical Bulletin, no. 103, MAPS 52, 1014, May 2017, http://onlinelibrary.wiley.com/doi/10.1111/maps.12888/full
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7579 approved meteorites from (Northwest Africa) (plus 1969 unapproved names)

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