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Northwest Africa 11784
Basic information Name: Northwest Africa 11784
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 11784
Observed fall: No
Year found: 2015
Country: (Northwest Africa)
Mass:help 235 g
Meteoritical Bulletin:  MB 107  (2018)  Ureilite
Recommended:  Ureilite    [explanation]

This is 1 of 630 approved meteorites classified as Ureilite.   [show all]
Search for other: Achondrites, Ureilites
Comments: Approved 26 May 2018
Writeup from MB 107:

Northwest Africa 11784 (NWA 11784)

(Northwest Africa)

Purchased: 27 Jul 2015

Classification: Ureilite

History: Purchased by Jay Piatek from a Moroccan meteorite dealer.

Physical characteristics: Single stone. A saw cut reveals medium grained, gray, pyroxene crystals with a mildly aligned orientation. Very fine, scattered metal and graphite grains are visible throughout.

Petrography: (C. Agee, UNM) Microprobe examination shows olivine, pigeonite, and augite grains, many in the size range ~1-2 mm. Graphite blades are present up to ~500 μm in length. Fine metal blebs and oxidized iron are observed along olivine grain boundaries. Olivines have oxidation-reduction rims.

Geochemistry: (C. Agee, UNM) Olivine Fa12.0±3.5, Fe/Mn=25±8, Cr2O3=0.61±0.02 CaO=0.29±0.03 (wt%), n=6; olivine cores Fa14.2±0.7, n=4; olivine rims Fa7.7±0.4, n=2; pigeonite Fs12.7±0.3Wo4.9±0.0, Fe/Mn=20±0, n=6; augite Fs8.1±0.1Wo35.4±0.4, Fe/Mn=16±1, n=5.

Classification: Ureilite, augite-bearing.

Specimens: 20.2 g on deposit at UNM, Jay Piatek holds the main mass.

Data from:
  Table 0
  Line 0:
Place of purchase:Morocco
Date:P 27 Jul 2015
Mass (g):234.6
Shock stage:low
Weathering grade:moderate
Fayalite (mol%):12.0±3.5
Ferrosilite (mol%):12.7±0.3, 8.1±0.1
Wollastonite (mol%):4.9±0.0, 35.4±0.4
Classifier:C. Agee, UNM
Type spec mass (g):20.2
Type spec location:UNM
Main mass:Jay Piatek
Comments:Field name JP-62; submitted by C. Agee, UNM
   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)
References: Published in Meteoritical Bulletin, no. 107, MAPS 55, 460-462
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     This is 1 of 9116 approved meteorites from (Northwest Africa) (plus 1873 unapproved names)

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