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Northwest Africa 16690
Basic information Name: Northwest Africa 16690
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 16690
Observed fall: No
Year found: 2023
Country: (Northwest Africa)
Mass:help 66 g
Recommended:  Lunar    [explanation]

This is 1 of 108 approved meteorites classified as Lunar.   [show all]
Search for other: Lunar meteorites
Comments: Approved 21 May 2024
Writeup from MB 113:

Northwest Africa 16690 (NWA 16690)

(Northwest Africa)

Purchased: 2023

Classification: Lunar meteorite

History: Purchased in 2023 by Habib-naji Naji from a meteorite dealer in Algeria.

Physical characteristics: Single stone with minor fusion crust.

Petrography: (D. Sheikh, Cascadia) Sample is a polymict breccia comprised of mm-sized lithic and mineral clasts/fragments, and agglutinates, set within a fine-grained matrix. Lithic clast lithologies identified include: anorthosites, noritic anorthosites, olivine gabbronorites, troctolites, basalts, impact melt clasts, and high-Fe clasts; mineral clasts identified include irregularly zoned olivines and pyroxenes. Accessory phases identified include Fe-Ni metal, troilite, silica, ilmenite, ulvospinel, Ca-phosphates, chromite, and chromian spinel.

Geochemistry: Olivine (Fa35.0±15.9, range Fa22.6-87.15, Fe/Mn=79±11, n=15), Low-Ca Pyroxene (Fs19.8±2.1Wo3.9±0.7, range Fs18.3-21.3Wo3.4-4.4, Fe/Mn=48±5, n=2), Pigeonite (Fs38.4±15.9Wo16.3±5.6, range Fs21.6-76.0Wo6.1-27.5, Fe/Mn=49±7, n=27), High-Ca Pyroxene (Fs41.0±17.7Wo32.6±5.4, range Fs10.0-60.5Wo25.0-41.0, Fe/Mn=51±12, n=8), Calcic Plagioclase (An95.9±2.0, range An87.6-98.2, n=28).

Classification: Lunar (regolith breccia) due to its brecciated nature, clast diversity, and the presence of agglutinates.

Specimens: 14 g at Cascadia, main mass with Habib-naji Naji.

Data from:
  Table 0
  Line 0:
Place of purchase:Algeria
Date:P 2023
Mass (g):66
Shock stage:high
Weathering grade:low
Fayalite (mol%):35.0±15.9
Ferrosilite (mol%):19.8±2.1, 38.4±15.9, 41.0±17.7
Wollastonite (mol%):3.9±0.7, 16.3±5.6, 32.6±5.4
Classifier:D. Sheikh, Cascadia
Type spec mass (g):14
Type spec location:Cascadia
Main mass:Habib-naji Naji
Comments:CML 1737; HN2; submitted by Daniel Sheikh
   and collections
Cascadia: Cascadia Meteorite Laboratory, Portland State University, Department of Geology, Room 17 Cramer Hall, 1721 SW Broadway, Portland, OR 97201, United States; Website (institutional address; updated 28 Oct 2011)
References: Published in Meteoritical Bulletin, no. 113, in preparation (2024)
Find references in NASA ADS:
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     This is 1 of 9829 approved meteorites from (Northwest Africa) (plus 1851 unapproved names)

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