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Northwest Africa 12693
Basic information Name: Northwest Africa 12693
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12693
Observed fall: No
Year found: 2018
Country: Mauritania
Mass:help 551 g
Classification
  history:
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 11 Jun 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12693 (NWA 12693)

Mauritania

Purchased: 2018

Classification: Ordinary chondrite (H4)

History: Reportedly found in 2018 by nomads in Mauritania. Purchased in Ensisheim from a Moroccan meteorite dealer, 2018.

Physical characteristics: Single stone, tetrahedron shaped, covered with fresh black fusion crust and contraction cracks; flow lines present. A cut surface shows a breccia with two different appearing lithologies. The host lithology has many distinct chondrules set in a dark-gray matrix; the secondary lithology within the host are angular fragments that appear to be more oxidized, with significant iron staining and chondrules that are less distinct.

Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows numerous chondrules; BR, BO, GO, and porphyritic observed, some with mesostasis. Plagioclase grain size <2 μm. Abundant metal and sulfide is present throughout.

Geochemistry: (C. Agee, UNM) Olivine Fa19.2±3.1, Fe/Mn=40±9, n=17; low-Ca pyroxene Fs16.4±0.3Wo1.5±0.6, Fe/Mn=9±3 n=10.

Classification: Ordinary chondrite (H4). Olivine is not fully equilibrated, but the presence of fine-grained plagioclase indicate a metamorphic type 4 rather than 3.

Specimens: 20 g on deposit at CSFK, probe mount at UNM, ZKereszty holds the main mass.

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Ensisheim
Date:P 2018
Mass (g):551
Pieces:1
Class:H4
Shock stage:S3
Weathering grade:W1
Fayalite (mol%):19.2±3.1
Ferrosilite (mol%):16.4±0.3
Wollastonite (mol%):1.5±0.6
Classifier:C. Agee, UNM
Type spec mass (g):20
Type spec location:CSFK
Main mass:ZKereszty
Comments:Field name ZK-15; submitted by C. Agee, UNM
Institutions
   and collections
UNM: Institute of Meteoritics MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 USA, United States; Website (institutional address; updated 12 Feb 2015)
ZKereszty: Gyor, Lahner 1. 9024 , Hungary (private address; updated 8 Sep 2014)
CSFK: Research Center for Astronomy and Earth Sciences, H-1121 Budapest, Konkoly Thege Miklós út 15-17.l Hungary, Hungary (institutional address; updated 7 Apr 2015)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108, in preparation (2019)
Find references in NASA ADS:
Find references in Google Scholar:
Photos:
CreditPhotos
Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
Zsolt Kereszty   
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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