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Northwest Africa 8687
Basic information Name: Northwest Africa 8687
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 8687
Observed fall: No
Year found: 2014
Country: (Northwest Africa)
Mass:help 563 g
Classification
  history:
Meteoritical Bulletin:  MB 103  (2014)  Lunar (troctolite)
Recommended:  Lunar    [explanation]

This is 1 of 88 approved meteorites classified as Lunar.   [show all]
Search for other: Lunar meteorites
Comments: Approved 13 Dec 2014
Writeuphelp
Writeup from MB 103:

Northwest Africa 8687 (NWA 8687)

(Northwest Africa)

Purchased: 2014

Classification: Lunar (troctolite)

History: Purchased by Adam Aaronson in Morocco, 2014.

Physical characteristics: Five pieces, no fusion crust, smooth, light green-tan color, sandblasted exterior, saw cut and polished surface reveals fine-grained, pale green interior with fine shock melt veining.

Petrography: (C. Agee, UNM) Microprobe examination of a ~30 × 15 mm, polished, saw-cut surface of the deposit sample, shows a monomict breccia with approximately 70% plagioclase, 25% olivine, 3% orthopyroxene. Primarily fine grained plagioclase, olivine, and orthopyroxene 5-50 μm, scattered larger plagioclase and olivine 200-500 μm, some poikioblastic plagioclase with fine-grained olivines and pyroxenes. Shock melt veins are found throughout. Scatterered Ti-chromite grains up to 100 μm, other accessory phases include FeNi-metal, troilite, ilmenite, and apatite. Minor pigeonite and augite present.

Geochemistry: (C. Agee and N. Muttik, UNM). olivine Fa21.7±2.2, Fe/Mn=88±5, n=24; low-Ca pyroxene Fs19.6±2.3Wo3.5±1.4, Fe/Mn=54±3, n=11; pigeonite Fs16.8Wo19.1, Fe/Mn=41, n=1; augite Fs11.3Wo37.2, Fe/Mn=41, n=1; plagioclase An96.7±0.8Ab3.1±0.8Or0.2±0.0, n=7; Shock melt (20 μm defocused electron beam, proxy for bulk meteorite composition): SiO2=43.01±0.66, TiO2=0.14±0.03, Al2O3=23.85±2.94, Cr2O3=0.15±0.05, MgO=12.11±3.05, FeO=5.20±1.17, MnO=0.06±0.01, CaO=13.48±1.32, NiO=0.02±0.02, Na2O=0.25±0.05, K2O=0.03±0.00 (all wt%), Fe/Mn=84±29, Mg#=80.5±0.8, n=5.

Classification: Achondrite (lunar troctolite), low weathering grade, high shock stage, likely paired with NWA 5744.

Specimens: A total of 21.5 g including a probe mount on deposit at UNM. Aaronson holds the main mass.

Data from:
  MB103
  Table 0
  Line 0:
Place of purchase:Morocco
Date:P 2014
Mass (g):562.5
Pieces:5
Class:Lunar (troctolite)
Shock stage:high
Weathering grade:low
Fayalite (mol%):21.7±2.2
Ferrosilite (mol%):19.6±2.3
Wollastonite (mol%):3.5±1.4
Classifier:C. Agee, UNM
Type spec mass (g):21.5
Type spec location:UNM
Main mass:Adam Aaronson
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)
Aaronson: Sahara Overland Ltd., Harhora, Temara, 12000, Morocco (private address; updated 3 Jan 2010)
Catalogs:
References: Published in Meteoritical Bulletin, no. 103, MAPS 52, 1014, May 2017, http://onlinelibrary.wiley.com/doi/10.1111/maps.12888/full
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Photos:
CreditPhotos
Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
Aeroliths Collection Theodossiou   
Bruno Caspirro   
Denis gourgues   
Emanuel Foglietto   
Russ Opdahl   
Solar Anamnesis   
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7187 approved meteorites from (Northwest Africa) (plus 2002 unapproved names)

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