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Northwest Africa 12841
Basic information Name: Northwest Africa 12841
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12841
Observed fall: No
Year found: 2010
Country: (Northwest Africa)
Mass:help 268 g
Classification
  history:
Meteoritical Bulletin:  MB 108  (2020)  L6
Recommended:  L6    [explanation]

This is 1 of 11582 approved meteorites (plus 10 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 3 Aug 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12841 (NWA 12841)

(Northwest Africa)

Purchased: 2010

Classification: Ordinary chondrite (L6)

History: Acquired by NHMV from Abdelaziz Mouadine (meteorite dealer in Austria) as part of a batch of unclassified Northwest Africa meteorites. The acquired stone was 267.8 g (6 × 5 × 4.5 cm).

Physical characteristics: Physical Characteristics: Brownish-black (no fusion crust; desert varnish) stone with a few open fractures (containing some remnants of soil). On the cut surface, a dense network of shock veins are visible, up to 1 mm in thickness, along with few metal grains.

Petrography: (L. Ferrière and S. Rajpriye, NHMV). This meteorite is moderately shocked, thermally metamorphosed, and altered. Chondrule boundaries are poorly defined. Most of the chondrules (fragments) are fractured and either of barred olivine or porphyritic olivine-pyroxene types. Minor opaque minerals and mostly recrystallized, fine-grained matrix surrounds chondrule fragments. Kamacite, taenite, tetrataenite, and troilite are present, along with few grains of merrillite and chlorapatite (up to 140 μm). Sparse chromite grains, up to 400 μm, are anhedral with rounded outlines and fractured. Minor oxide rims are present around a number of metal and troilite grains. A network of shock veins is present (up to 1 mm thick). Large ringwoodite grains (up to few 100 μm) are visible within some of the veins. Melt pockets also occur.

Geochemistry: (L. Ferrière, S. Rajpriye, and D. Topa, NHMV). Olivine in the matrix is Fa24.3±0.3 (23.8-25.0), Fe/Mn: 50.2±2.6 (N=19) and in chondrule fragments is Fa24.0±0.3 (Fa23.6-24.5), Fe/Mn: 50.7±3.8 (N=6). Low Ca-Pyroxene: in matrix Fs20.1±0.3Wo1.5±0.1 (Fs19.8-21.0Wo1.3-1.8), Fe/Mn: 29.3±1.8 (N=21) and in chondrules is Fs20.0±0.2Wo1.3±0.1 (Fs19.7-20.3Wo1.2-1.4), Fe/Mn: 26.6±1.6 (N=5). High Ca-Pyroxene: Fs7.2±0.7Wo44.1±0.5 (Fs6.7-7.6Wo43.7-44.4) and Fe/Mn: 21.3 (N=2). Plagioclase: An10.1± 0.37Ab 83.4±0.7Or6.6±0.5 (An9.7-11.5Ab81.3-84.0Or6.0-8.0) (N=22). Kamacite: Ni 6.1±0.3 (5.4-6.6), Co 0.85±0.16 (N=17); Taenite: Ni 29.0±2.7 (25.1-34.7), Co 0.25±0.06 (N=16). Tetrataenite: Ni49.9±2.1 (46.9-52.0), Co 0.12±0.04 (N=5). Chromite: Cr# 0.88 and Fe# 0.88.

Classification: Ordinary Chondrite (L6), S4, W2

Specimens: The entire specimen (NHMV-N8623; 262.83 g) as well as one polished thin section (NHMV-O1154) are at NHMV.

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Vienna, Austria
Date:P 2010
Mass (g):267.8
Pieces:1
Class:L6
Shock stage:S4
Weathering grade:W2
Fayalite (mol%):24.3±0.3 (N=19)
Ferrosilite (mol%):20.1± 0.3(N=21)
Wollastonite (mol%):1.5±0.1
Magnetic suscept.:4.46
Classifier:L. Ferrière and S. Rajpriye, NHMV
Type spec mass (g):262.8
Type spec location:NHMV
Main mass:NHMV
Comments:Submitted by L. Ferrière
Institutions
   and collections
NHMV: Naturhistorisches Museum, Burgring 7, 1010 Wien, Austria, Austria; Website (institutional address; updated 18 Jan 2019)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7937 approved meteorites from (Northwest Africa) (plus 1960 unapproved names)

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