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Northwest Africa 12532
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:help 2 kg
Classification
  history:
Meteoritical Bulletin:  MB 108  (2020)  LL6
Recommended:  Brachinite    [explanation]

This is 1 of 54 approved meteorites classified as Brachinite.   [show all]
Search for other: Brachinites, Primitive achondrites
Comments: Approved 11 Oct 2019
Revised 18 Jul 2021: revised classification
Writeuphelp
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:
Place of purchase:Rissani
Date:P 2019
Mass (g):2000
Pieces:1
Class:LL6
Shock stage:C-S2
Weathering grade:W3
Fayalite (mol%):27.6±0.1
Ferrosilite (mol%):24.2±0.2; 9.7±0.2
Wollastonite (mol%):1.8±0.0; 43.6±0.3
Classifier:A. Love, App
Type spec mass (g):20.05
Type spec location:App
Main mass:J. Sinclair
Finder:Unknown
Comments:Submitted by Anthony Love
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)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
Published in Meteoritical Bulletin, no. 110, in preparation (2021)
Find references in NASA ADS:
Find references in Google Scholar:
Photos:
CreditPhotos
Public domain photographs:
Anthony Love   
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7937 approved meteorites from (Northwest Africa) (plus 1960 unapproved names)

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