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Northwest Africa 7871
Basic information Name: Northwest Africa 7871
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 7871
Observed fall: No
Year found: 2004
Country: (Northwest Africa)
Mass:help 450 g
Meteoritical Bulletin:  MB 102  (2013)  L6
Recommended:  L6    [explanation]

This is 1 of 12899 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 9 May 2013
Writeup from MB 102:

Northwest Africa 7871 (NWA 7871)

(Northwest Africa)

Purchased: Feb 2004

Classification: Ordinary chondrite (L6)

History: The rock was obtained by Edwin Thompson from a Moroccan trader at the Tucson Gem and Mineral Show and a portion was donated to Cascadia in February 2004.

Physical characteristics: The rock has facets with a brown, slightly bumpy exterior surface, rare remnant fusion crust, and a brownish interior in cut faces.

Petrography: (K. Armstrong and A. Ruzicka, Cascadia) The specimen shows granoblastic texture with indistinct chondrules (mean diameter = 0.4 ± 0. 3 mm) and transparent matrix. A metal-poor igneous-textured inclusion (up to 1.1 cm across) is present. About 20% of metal has been replaced by terrestrial weathering products; calcite produced by terrestrial weathering fills cracks. The abundance of metal and troilite determined by pixel counting in reflected light images is 3.5±0.8 and 2.7±1.5 area%, respectively.

Geochemistry: Olivine Fa26.7±1.1 Fe/Mn=51.6±6.5 (N=40) and low-Ca pyroxene Wo1.5±0.3 Fs22.3±0.7 Fe/Mn = 29.7±2.56 (N=6).

Classification: Data permit L6 and LL6 designations but overall appearance and Fe/Mn of silicates are typical of L6. Weathering grade close to W1/2 boundary but probably more typical of W2.

Specimens: 30 g in two pieces, one polished thin section, and one butt are available at CascadiaThompson holds the main mass.

Data from:
  Table 0
  Line 0:
Place of purchase:Tuscon, Arizona
Date:P Feb 2004
Mass (g):450
Shock stage:S3
Weathering grade:W2
Fayalite (mol%):26.7±1.1
Ferrosilite (mol%):22.3±0.7
Wollastonite (mol%):1.5±0.3
Classifier:K. Armstrong and A. Ruzicka, Cascadia
Type spec mass (g):30
Type spec location:Cascadia
Main mass:Edwin Thompson
Comments:Lab Sample CML0178; 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. 102, MAPS 50, 1662, September 2015
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     This is 1 of 9772 approved meteorites from (Northwest Africa) (plus 1862 unapproved names)

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