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| Northwest Africa 12532 | |||||||||||||||||||||||||||||||||
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| Basic information | Name: Northwest Africa 12532 This is an OFFICIAL meteorite name. Abbreviation: NWA 12532 Observed fall: No Year found: 2019 Country: (Northwest Africa) Mass:  2 kg | ||||||||||||||||||||||||||||||||
| Classification history: |
This is 1 of 55 approved meteorites classified as Brachinite. [show all] Search for other: Brachinites, Primitive achondrites | ||||||||||||||||||||||||||||||||
| Comments: |
Approved 11 Oct 2019 Revised 18 Jul 2021: revised classification | ||||||||||||||||||||||||||||||||
| Writeup |
Writeup from MB 108:
Northwest Africa 12532 (NWA 12532) (Northwest Africa) Purchased: 2019 Classification: Ordinary chondrite (LL6) History: One large uncrusted 2000g stone was found in Western Sahara in 2018. John Sinclair purchased the sample from a meteorite prospector at the Tucson Gem and Mineral Show in 2019. Physical characteristics: Sample lacks a fusion crust, is yellowish-orange in color and crystalline. Cut face shows a granoblastic texture and dark colored-opaque grains. Petrography: Description and classification (A. Love, App): Sample shows a granoblastic texture composed of 517 µm olivine, low-Ca pyroxene, twinned Cpx and twinned plagioclase that meet at 120º grain boundaries. Additional minerals are phosphates, troilite, chromite, and oxidized FeNi metal grains. Geochemistry: (A. Love, App) Olivine: Fa27.6±0.1, Fe/Mn 51.9±1.3, n=10; low Ca pyroxene Fs24.2±0.2Wo1.8±0.0, Fe/Mn=34.8±0.6, n=8; high Ca pyroxene Fs9.7±0.2Wo43.6±0.3, N=3; plagioclase Ab57.4±0.3Or0.3±0.0, N=3. Classification: LL6. Sample is an LL based on mineral compositions, and is type 6 based on recrystallized granoblastic texture. Specimens: John Sinclair holds the main mass. One endcut weighing 20.05 g and a polished mount and thin section are on deposit at App. Writeup from MB 110: Northwest Africa 12532, reclassification Geochemistry: (A. Love, App) revised low-Ca pyroxene (Fs22.90±0.04Wo2.10±0.04, Fe/Mn=31.70±0.83, n=14); revised plagioclase (An40.27±0.18Or0.49±0.03, n=5). Oxygen isotopes (K. Ziegler, UNM): analyses of 3 acid-washed subsamples by laser fluorination gave, δ17O =2.345, 2.713, 2.456; δ18O =4.908, 5.573, 5.119; Δ17O = -0.246, -0.229, -0.247 (all per mil). Classification: Brachinite. Ferromagnesian silicates have compositions and Fe/Mn ratios that fall within the brachinites. The oxygen isotope compositions fall below the TFL along the array for brachinites. Magnetic susceptibility falls within the range defined for brachinites. | ||||||||||||||||||||||||||||||||
| Data from: MB108 Table 0 Line 0: |
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| 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) App: Department of Geology, 572 Rivers St., Appalachian State University, Boone, NC 28608, United States (institutional address; updated 7 Mar 2013) |
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| References: | Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150 Published in Gattacceca J., McCubbin F.M., Grossman J., Bouvier A., Chabot N.L., D'Orazio M., Goodrich C., Greshake A., Gross J., Komatsu M., Miao B., and Schrader D. (2022) The Meteoritical Bulletin, No. 110. Meteorit. Planet. Sci. 1-4
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| Photos: |
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| Geography: |
Statistics: This is 1 of 9092 approved meteorites from (Northwest Africa) (plus 1875 unapproved names) | ||||||||||||||||||||||||||||||||