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Northwest Africa 13917
Basic information Name: Northwest Africa 13917
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 13917
Observed fall: No
Year found: 2020
Country: (Northwest Africa)
Mass:help 5.2 kg
Classification
  history:
Recommended:  Winonaite    [explanation]

This is 1 of 55 approved meteorites classified as Winonaite.   [show all]
Search for other: Primitive achondrites, Winonaites
Comments: Approved 6 May 2021
Writeuphelp
Writeup from MB 110:

Northwest Africa 13917 (NWA 13917)

(Northwest Africa)

Purchased: 2020

Classification: Primitive achondrite (Winonaite)

History: Purchased from Morocco in September 2020 and January 2021.

Physical characteristics: Several identical appearing stones found together -- the largest of which are individuals weighing 1.6 kg, 1.4 kg, and 1.2 kg. Saw-cut surface shows abundant fine-grained metal and sulfide set in a mosaic of brown and gray silicate minerals. A prominent metal vein 2 mm thick and several cm in length crosscuts the deposit sample slice.

Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows a texturally equilibrated mosaic of enstatite and diopside with grain size in the range 100-300 μm, many triple junctions are present. Forsterite is ubiquitous but is significantly less abundant than the pyroxenes. Kamacite, taenite, and troilite make up approximately 10% of this meteorite, most grains are 100-300 μm in diameter. A phosphate phase was detected. No feldspar was observed in the microprobe mount.

Geochemistry: (C. Agee UNM) Forsterite Fa4.0±0.0, Fe/Mn=16±0, n=2; enstatite Fs4.7±0.2Wo1.9±0.2, Fe/Mn=13±1, n=3; diopside Fs1.3±0.4Wo44.8±0.3, Fe/Mn=13±7, n=4. Oxygen isotopes (K. Ziegler, UNM): 3 acid-washed fragments analyzed by laser fluorination gave δ18O=4.959, 5.107, 5.236; δ17O=2.055, 2.179, 2.232; Δ17O=-0.563, -0.518, -0.533 (linearized, all per mil, TFL slope=0.528).

Classification: Primitive achondrite (Winonaite)

Specimens: 67.9 g on deposit at UNM. Mark Lyon holds the main masses.

Data from:
  MB110
  Table 0
  Line 0:
Place of purchase:Morocco
Date:P 2020
Mass (g):5.2 kg
Pieces:several
Class:Winonaite
Shock stage:low
Weathering grade:moderate
Fayalite (mol%):4.0±0.0
Ferrosilite (mol%):4.7±0.2, 1.3±0.4
Wollastonite (mol%):1.9±0.2, 44.8±0.3
Classifier:C. Agee, UNM
Type spec mass (g):67.9
Type spec location:UNM
Main mass:Mark Lyon
Comments:Submitted by C. Agee
Plots: O isotopes:  
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. 110, in preparation (2021)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7727 approved meteorites from (Northwest Africa) (plus 1972 unapproved names)

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