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Northwest Africa 7499
Basic information Name: Northwest Africa 7499
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 7499
Observed fall: No
Year found: 2012
Country: Morocco
Mass:help 320 g
Classification
  history:
Meteoritical Bulletin:  MB 101  (2012)  Brachinite
Recommended:  Brachinite    [explanation]

This is 1 of 55 approved meteorites classified as Brachinite.   [show all]
Search for other: Brachinites, Primitive achondrites
Comments: Approved 8 Nov 2012
Writeuphelp
Writeup from MB 101:

Northwest Africa 7499 (NWA 7499)

Morocco

Purchased: August 2012

Classification: Primitive achondrite (Brachinite)

History: Purchased by Adam Bates in Morocco, August 2012.

Physical characteristics: Nine matching stones, the largest 162 g. Weathered exterior with mineral grains exposed, broken surface reveals mostly equant honey-colored olivine crystals and a few chromium-green pyroxene crystals, scattered metal/chromite/sulfide grains.

Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows approximately 75% olivine, 20% low-Ca pyroxene, texturally equilibrated with triple junctions, silicate grain size 100-700 μm. Accessory chromite, Fe-Ni metal, Fe-sulfide, with minor Cl-rich apatite and high-Ca pyroxene, no plagioclase detected. About 10-20% of metal is oxidized, many oxidation veinlets on grain boundaries.

Geochemistry: (C. Agee and L. Burkemper, UNM) Olivine Fa29.9±0.3, Fe/Mn=65±3, n=12; low-Ca pyroxene Fs24.4±0.2Wo2.1±0.1, Fe/Mn=40±3, n=11; high-Ca pyroxene Fs10.1Wo43.0, Fe/Mn=31±10; metal Fe 86% Ni 14%.

Classification: Primitive achondrite (brachinite)

Specimens: 21.32 g including a probe mount on deposit at UNM, Adam Bates holds the main mass.

Data from:
  MB101
  Table 0
  Line 0:
Place of purchase:Morocco
Date:P August 2012
Mass (g):320
Pieces:9
Class:Brachinite
Fayalite (mol%):29.9±0.3
Ferrosilite (mol%):24.4±0.2
Wollastonite (mol%):2.1±0.1
Classifier:C. Agee, UNM
Type spec mass (g):21.32
Type spec location:UNM
Main mass:Adam Bates
Comments:Submitted by C. Agee
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)
Catalogs:
References: Published in Meteoritical Bulletin, no. 101, MAPS 50, 1661, September 2015
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Geography:

Morocco
Coordinates:Unknown.

Statistics:
     This is 1 of 1852 approved meteorites from Morocco (plus 24 unapproved names) (plus 1 impact crater)

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