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Northwest Africa 12240
Basic information Name: Northwest Africa 12240
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12240
Observed fall: No
Year found: 2017
Country: Mauritania
Mass:help 1808 g
Classification
  history:
Meteoritical Bulletin:  MB 107  (2018)  H4
Recommended:  H4    [explanation]

This is 1 of 5964 approved meteorites (plus 2 unapproved names) classified as H4.   [show all]
Search for other: H chondrites, H chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 20 Oct 2018
Revised 6 Nov 2018: Corrections to mass
Writeuphelp
Writeup from MB 107:

Northwest Africa 12240 (NWA 12240)

Mauritania

Find: 2017

Classification: Ordinary chondrite (H4)

Petrography: The rock contains well-defined RP, PP, PO, and BO chondrules ranging from 80 to 1100 µm in diameter and averaging ~400 µm. Opaques include metallic Fe-Ni, troilite and chromite. There are many shock features: (1) Most troilite grains are polycrystalline. (2) Some kamacite grains contain small irregular grains of troilite, some also containing metallic Cu (up to 8x30 µm in size) adjacent to the trolite. (3) Also present are chromite-plagioclase assemblages and chromite veinlets inside olivine grains. The typical plagioclase grain is 5-10 µm in size. All of the low-Ca pyroxene grains are orthorhombic.

Data from:
  MB107
  Table 0
  Line 0:
Place of purchase:CFMS show in Ventura, CA
Date:2017
Mass (g):1808.4
Pieces:8
Class:H4
Shock stage:S2
Weathering grade:W1
Fayalite (mol%):19.0±2.9 (n=22)
Ferrosilite (mol%):17.6±3.0 (n=18)
Wollastonite (mol%):1.1±0.5 (n=18)
Classifier:A. Rubin, UCLA
Type spec mass (g):53.3
Type spec location:UCLA
Main mass:Michael Santos, StarStruck Meteorites
Comments:Submitted by Simone de Leuw
Institutions
   and collections
UCLA: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095-1567, United States (institutional address; updated 17 Oct 2011)
Catalogs:
References: Published in Meteoritical Bulletin, no. 107, MAPS 55, 460-462
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Geography:

Mauritania
Coordinates:Unknown.

Statistics:
     This is 1 of 127 approved meteorites from Mauritania (plus 1 unapproved name) (plus 2 impact craters)

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