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Northwest Africa 12992
Basic information Name: Northwest Africa 12992
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12992
Observed fall: No
Year found: 2017
Country: (Northwest Africa)
Mass:help 222 g
Classification
  history:
Meteoritical Bulletin:  MB 108  (2020)  LL6
Recommended:  LL6    [explanation]

This is 1 of 2817 approved meteorites (plus 1 unapproved name) classified as LL6.   [show all]
Search for other: LL chondrites, LL chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 21 Nov 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12992 (NWA 12992)

(Northwest Africa)

Find: 2016

Classification: Ordinary chondrite (LL6)

Physical characteristics: Hand specimen is considerably weathered and pitted, with partial fusion crust.

Petrography: Chondrules are dominantly porphyritic with typical size of 600-700 µm. Few exhibit discernible edges but most are poorly delineated and chondrule fragments blend in with the recrystallized matrix. Metal grains average at 100-200 µm in length with modal abundance of ~2 %. Olivines are mostly 200-400 µm, pyroxenes 300-400 µm and plagioclase 100-200 µm in length. Minor chromite and apatite are observed.

Geochemistry: Mineral composition and geochemistry: All analyses by EPMA. Metal: predominantly kamacite with 5.4±0.3 wt% Ni and 2.4±0.3 wt% Co, taenite with 32.6-51.7 wt% Ni and 0.5±0.1 wt% Co. All troilite and chromite analyses had low totals due to weathering. Olivine: Fa28.8±0.3 (N=42). Pyroxene: Fs24.4±0.5En73.9±1.0Wo1.8±0.8 (N=29). Plagioclase: Ab86.5±2.7An11.2±2.9Or2.2±0.7 (N=23)

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Morocco
Date:2016
Mass (g):222
Pieces:1
Class:LL6
Weathering grade:W2
Fayalite (mol%):28.8±0.3 (N=42)
Ferrosilite (mol%):24.4±0.5 (N=29)
Wollastonite (mol%):1.8±0.8
Classifier:I. S. Mattia, ICL, and N. V. Almeida, NHM
Type spec mass (g):21.3
Type spec location:NHM
Main mass:Jasper Spencer
Comments:Submitted by N. V. Almeida
Institutions
   and collections
NHM: Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom; Website (institutional address; updated 9 Dec 2011)
ICL: Impacts and Astromaterials Research Centre, Department of Earth Science and Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, United Kingdom (institutional address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

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

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