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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 98 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   
Dirk Hohmann         
Paulo Anselmo Matioli (JN Science Museum)   
Russ Opdahl   
Solar Anamnesis         
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 8495 approved meteorites from (Northwest Africa) (plus 1899 unapproved names)

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