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Northwest Africa 12736
Basic information Name: Northwest Africa 12736
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12736
Observed fall: No
Year found: 2015
Country: (Northwest Africa)
Mass:help 10.9 g
Classification
  history:
Recommended:  Achondrite-ung    [explanation]

This is 1 of 89 approved meteorites classified as Achondrite-ung.   [show all]
Search for other: Achondrites, Ungrouped achondrites
Comments: Approved 31 Jan 2020
Writeuphelp
Writeup from MB 109:

Northwest Africa 12736 (NWA 12736)

(Northwest Africa)

Purchased: 2015

Classification: Achondrite-ung

Petrography: (J. Gattacceca, CEREGE) Blocky aggreagte of olivine and pyroxene with grain size 600 µm. Metal and troilite are present as veinlets, along silicate rims and as small aligned crystals within silicates. No graphite was observed; and no silicate zoning was observed.

Geochemistry: Olivine Fa12.2±0.6, FeO/MnO 23.4±4.5, CaO 0.26±0.04 wt%, Cr2O3 0.50±0.04 wt% (n=6). Pyroxene: low-Ca pyroxene Fs10.9±0.2Wo4.7±0.1 (n=5), high-Ca pyroxene Fs6.6±0.1Wo37.8±0.3 (n=5), FeO/MnO 12.8±2.7 (n=10). Oxygen isotopic composition (J. Gattacceca, C. Sonzogni, CEREGE) from analysis of one acid-washed 1.5 mg aliquot of a powdered 118 mg bulk sample is δ17O=0.05‰, δ18O=1.65‰ , Δ17O=-0.81‰ (linearized, slope 0.5247, analytical uncertainties 0.08‰, 0.12‰, 0.03‰ respectively).

Classification: Achondrite-ungrouped. The mineralogy is reminiscent of ureilites but significant differences are the absence of carbon material (graphite, diamond) and the absence of reduced rim in silicates. Owygen isotopic composition is also distinct from that of ureilites.

Data from:
  MB109
  Table 0
  Line 0:
Place of purchase:Erfoud
Date:P 2015
Mass (g):10.91
Pieces:1
Class:Achondrite-ung
Weathering grade:low
Fayalite (mol%):12.2±0.6 (n=6)
Ferrosilite (mol%):10.9±0.2 (n=5)
Wollastonite (mol%):4.7±0.1 (n=5)
Magnetic suscept.:4.23
Classifier:J. Gattacceca, CEREGE
Type spec mass (g):2.27
Type spec location:CEREGE
Main mass:Pierre-Marie Pelé
Finder:anonymous
Comments:work name PM19U1; submitted by Jérôme Gattacceca
Plots: O isotopes:  
Institutions
   and collections
CEREGE: CEREGE BP 80 Avenue Philibert, Technopole de l'Arbois 13545 Aix-en-Provence Cedex 4 France, France (institutional address; updated 29 Oct 2018)
Catalogs:
References: Published in Meteoritical Bulletin, no. 109, in preparation (2020)
Find references in NASA ADS:
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Photos:
CreditPhotos
Public domain photographs:
Jerome Gattacceca      
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7171 approved meteorites from (Northwest Africa) (plus 2003 unapproved names)

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