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Northwest Africa 13854
Basic information Name: Northwest Africa 13854
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 13854
Observed fall: No
Year found: 2021
Country: (Northwest Africa)
Mass:help 792 g
Classification
  history:
Recommended:  Mesosiderite    [explanation]

This is 1 of 217 approved meteorites classified as Mesosiderite.   [show all]
Search for other: Mesosiderites, Metal-rich meteorites
Comments: Approved 25 Apr 2021
Writeuphelp
Writeup from MB 110:

Northwest Africa 13854 (NWA 13854)

(Northwest Africa)

Purchased: 2021

Classification: Mesosiderite

History: The meteorite was purchased from a dealer in Morocco.

Physical characteristics: Dark brownish fragment without fusion crust.

Petrography: The meteorite displays a light brownish interior and consists of silicate (about 60 vol%) and metallic (about 40 vol%) portions. The silicate fraction is largely composed of low-Ca pyroxene up to 8 mm (sometimes weakly compositionally zoned) and angular calcic plagioclase grains up to 1 mm. Ca-pyroxene is present as blebby and lamellar exsolutions in low-Ca pyroxene. Plagioclase often poikilitically encloses smaller pyroxene grains. Sparse olivine show reaction coronas with pyroxene and contain symplectitic orthopyroxene-chromite inclusions. Minor phases are silica, Ti-chromite, ilmenite, FeS, and Mg-merrillite. Kamacite and taenite constitute the metallic portion and are present as up to 6 mm sized irregular shaped aggregates dispersed throughout the rock.

Geochemistry: low-Ca pyroxene: Fs29.3±0.6Wo4.5±0.2 (Fs28.6-30.3Wo4.2-5.0, FeO/MnO=24-27, n=10); augite exsolutions: Fs16.5±0.6Wo39.0±0.9 (Fs15.9-17.6Wo37.1-39.8, FeO/MnO=19-21, n=9); olivine: Fa32.4±0.4 (Fa31.7-33.1, FeO/MnO=41±2, n=11); calcic plagioclase: An86.5±3.4 (An83.3-92.8, n=11)

Data from:
  MB110
  Table 0
  Line 0:
Place of purchase:Morocco
Date:P 2021
Mass (g):792
Pieces:5
Class:Mesosiderite
Shock stage:S1
Weathering grade:low
Fayalite (mol%):32.4
Ferrosilite (mol%):29.3; 16.5
Wollastonite (mol%):4.5; 39.0
Classifier:A. Greshake, MNB
Type spec mass (g):23.7
Type spec location:MNB
Main mass:Philippe Schmitt-Kopplin
Comments:Submitted by Ansgar Greshake
Institutions
   and collections
MNB: Museum für Naturkunde, Invalidenstraße 43, D-10115 Berlin, Germany (institutional address; updated 24 Dec 2011)
Catalogs:
References: Published in Meteoritical Bulletin, no. 110, in preparation (2021)
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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