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| Northwest Africa 12922 | |||||||||||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 12922 This is an OFFICIAL meteorite name. Abbreviation: NWA 12922 Observed fall: No Year found: 2019 Country: (Northwest Africa) Mass:  20.3 g | ||||||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 83 approved meteorites classified as CK6. [show all] Search for other: Carbonaceous chondrites, Carbonaceous chondrites (equilibrated), CK chondrites, CK chondrites (type 4-6), and CV-CK clan chondrites | ||||||||||||||||||||||||||||||||||
| Comments: | Approved 21 Nov 2019 | ||||||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 108:
Northwest Africa 12922 (NWA 12922) (Northwest Africa) Purchased: 2019 Classification: Carbonaceous chondrite (CK6) History: A single stone weighing 20.3 g was found in Western Sahara prior to 2019. The sample was purchased by John Sinclair and J. Donald Cline at the Tucson Gem and Mineral show in 2019. Physical characteristics: Sample is dark grayish-black in color, and has a weakly tabular shape. The sample is partially covered in a weathered black fusion crust with contraction cracks. A cut face shows the interior is composed of a dark brownish assemblage of rounded chondrules set within a dark matrix. Petrography: Description and classification (A. Love, App): Sample shows a recrystallized chondritic texture composed of indistinct chondrules set within a recrystallized, olivine-dominated, opaque-rich matrix. Porphyritic and granular olivine chondrules have an average diameter of 672 μm Additional minerals are: low-Ca pyroxene, pigeonite, Ca-pyroxene, Cr-bearing magnetite, zoned plagioclase feldspar, rare troilite and rare alkali feldspar. Geochemistry: (A. Love, App): Olivine (Fa30.5±0.3, Fe/Mn=93.1±2.6, NiO=0.4±0.0, n=10); low Ca pyroxene (Fs26.7±1.4Wo1.7±1.6 (Fs24.5-3.2Wo0.5-4.8), Fe/Mn=61.9±4.2, n=6); pigeonite (Fs22.1±0.7Wo12.9±2.7 (Fs21.3-22.7Wo9.8-14.8), Fe/Mn=58.2±2.2, n=3); Ca pyroxene (Fs10.6Wo42.1, n=1); plagioclase: (An43.9±10.4Or3.2±2.2, n=5); Cr-Magnetite contains 4.2Wt% Cr2O3. Classification: Carbonaceous Chondrite (CK6 C-S2 W3). Chondrule size, magnetic susceptibility, Cr-bearing magnetite and Fe/Mn of olivine and pyroxene are consistent with CK. Equilibrated compositions of olivine, indistinct, yet visible chondrules and size of plagioclase grains (>100µm) characterize this sample as CK6. Specimens: PARI holds the main mass. A polished thin section and endcut weighing 4.1 g are on deposit at App. | ||||||||||||||||||||||||||||||||||
| Data from: MB108 Table 0 Line 0: |
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| Institutions and collections |
App: Department of Geology, 572 Rivers St., Appalachian State University, Boone, NC 28608, United States (institutional address; updated 7 Mar 2013) PARI: Pisgah Astronomical Research Institute 1 Pari Dr Rosman, NC 28772, United States (institutional address; updated 13 Sep 2016) |
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| Catalogs: |
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| References: | Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
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| Geography: |
Statistics: This is 1 of 9710 approved meteorites from (Northwest Africa) (plus 1853 unapproved names) | ||||||||||||||||||||||||||||||||||
| Also see: |
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| Revision history: |
This lists important revisions made to data for this record.
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