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Northwest Africa 13219 | |||||||||||||||||||||||||||||
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Basic information | Name: Northwest Africa 13219 This is an OFFICIAL meteorite name. Abbreviation: NWA 13219 Observed fall: No Year found: 2019 Country: Niger Mass: ![]() | ||||||||||||||||||||||||||||
Classification history: |
This is 1 of 55 approved meteorites classified as Eucrite-cm. [show all] Search for other: Achondrites, Eucrites, and HED achondrites | ||||||||||||||||||||||||||||
Comments: | Approved 5 Apr 2020 | ||||||||||||||||||||||||||||
Writeup![]() |
Writeup from MB 109:
Northwest Africa 13219 (NWA 13219) Niger Purchased: 2019 August Classification: HED achondrite (Eucrite, cumulate) History: Purchased over the Internet from anonymous finder; said to be from Niger; shipped from Mauritania. Physical characteristics: A nearly-whole, oriented individual stone covered 90% in a dark-brown and spotted fusion-crust which has flow-lines and over-lipping. The fusion crust has a distinctive, locally translucent appearance, with "spots" where the fusion crust is clear (dependent upon the minerals in the underlying stone). Petrography: This highly shocked breccia consists dominantly of pyroxene and plagioclase (now partly maskelynite). Vaguely discernible vestiges of the original texture suggest grains up to 3.5 mm (plagioclase) but conceivably even coarser; most of the material has been granulated to <<1 mm. Accessory phases include Cr-spinel, Fe-metal, troilite, and a glassy shock-melt vein. Within a few relatively ungranulated pyroxene grains, exsolved augite lamellae are seen to be about 5-8 µm wide. Classification as a cumulate eucrite is based on geochemistry (see below), not the severely impact-modified texture. Geochemistry: Low-Ca pyroxene (10 analyses) clusters near Fs36.4Wo4.3. High-Ca pyroxene blebs and lamellae (3 analyses) cluster near Fs18.6Wo37.9. Pyroxene FeO/MnO (wt; 14 analyses) averages 28.2. Plagioclase (8 analyses) is An92.3-95.3, average An93.9±1.0. Classification as a cumulate eucrite is based on geochemistry (magnesian mafic silicates, Na-poor plagiolcase, little if any ilmenite), not texture. Analyses (2) of a glassy shock-melt vein average 18.0 wt% Al2O3 with FeO/MgO (wt) = 1.09. Classification: Eucrite, cumulate, brecciated. Specimens: 24 grams at UCLA; main mass with Verish. | ||||||||||||||||||||||||||||
Data from: MB109 Table 0 Line 0: |
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Institutions and collections |
UCLA: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095-1567, United States (institutional address; updated 17 Oct 2011) Verish: Robert Verish, Meteorite-Recovery Lab, P.O. Box 463084, Escondido, CA 92046, United States; Website (private address; updated 27 May 2009) |
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Catalogs: |
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References: | Published in Meteoritical Bulletin, no. 109, in preparation (2020)
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Photos: |
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Geography:![]() |
Statistics: This is 1 of 117 approved meteorites from Niger (plus 4 unapproved names) |