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Northwest Africa 12757
Basic information Name: Northwest Africa 12757
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12757
Observed fall: No
Year found: 2015
Country: (Northwest Africa)
Mass:help 298 g
Classification
  history:
Recommended:  Eucrite    [explanation]

This is 1 of 431 approved meteorites (plus 1 unapproved name) classified as Eucrite.   [show all]
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 18 Aug 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12757 (NWA 12757)

(Northwest Africa)

Purchased: 2015

Classification: HED achondrite (Eucrite)

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

Physical characteristics: Grayish rock with some fusion crust.

Petrography: Monomict breccia composed of up to 6 mm sized mineral fragments which are predominantly exsolved pyroxene and calcic plagioclase. Pyroxene is either augite with low-Ca exsolution lamellae or vice versa. Plagioclase shows signs of recrystallization. Minor phases include Fe-rich olivine, silica, FeS, chromite, and barite; no metallic Fe has been found. Contains shock melt.

Geochemistry: low-Ca pyroxene: Fs65.7±2.4Wo2.9±0.8 (Fs60.3-67.6Wo2.2-4.9, n=12, FeO/MnO=25-34); Ca-pyroxene: Fs29.3±2.5Wo42.5±0.7 (Fs26.4-32.6Wo40.6-43.0, n=11, FeO/MnO=29-35); olivine: Fa81.6±3.2 (Fa75.6-84.8, n=19, FeO/MnO=37±7); calcic plagioclase: An90.7±1.1 (An88.2-92.0, n=12)

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Morocco
Date:P 2015
Mass (g):298
Pieces:1
Class:Eucrite
Shock stage:high
Weathering grade:low
Ferrosilite (mol%):65.7; 29.3
Wollastonite (mol%):2.9; 42.5
Classifier:A. Greshake, MNB
Type spec mass (g):20.3
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)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108, in preparation (2019)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 6900 approved meteorites from (Northwest Africa) (plus 2035 unapproved names)

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