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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 Meteoritical Bulletin, no. 110, in preparation (2021)
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| Photos: |
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| Geography: |
Statistics: This is 1 of 8495 approved meteorites from (Northwest Africa) (plus 1899 unapproved names) | ||||||||||||||||||||||||||||||||