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Northwest Africa 12230
Basic information Name: Northwest Africa 12230
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12230
Observed fall: No
Year found: 2017
Country: (Northwest Africa)
Mass:help 1024 g
Classification
  history:
Recommended:  Eucrite-pmict    [explanation]

This is 1 of 337 approved meteorites classified as Eucrite-pmict.   [show all]
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 13 Nov 2018
Writeuphelp
Writeup from MB 107:

Northwest Africa 12230 (NWA 12230)

(Northwest Africa)

Purchased: 2017

Classification: HED achondrite (Eucrite, polymict)

History: 34 identical stones with a total weight 1024.7 g were found by a meteorite prospector in Morocco. John Sinclair purchased the specimens at the 2017 Tucson Gem and Mineral Show.

Physical characteristics: The stones have a dark-brownish-gray weathered exterior that has a granular texture and contains circular pits where clasts have been plucked out. The cut face of the interior is dark greenish-grey and shows a brecciated texture composed of lithic clasts and mineral fragments.

Petrography: Description and classification (A. Love, App): Sample is a polymict breccia composed of rounded to irregular-shaped mineral clasts and sparse lithic clasts (up to 2 cm) from cumulate and vitrophyric eucrites, and diogenites (~6 vol%). Pyroxenes are exsolved. Accessory minerals are FeNi grains, silica polymorph, ilmenite, chromite and olivine.

Geochemistry: (A. Love, App) Pigeonite host: Fs51.4±9.8Wo5.8±2.3 (Fs34.8-65.6Wo3.6-9.3, FeO/MnO=27.4-34.2), N=8; high-Ca pyroxene exsolution lamellae: Fs26.2±5.8Wo40.5±0.9 (Fs20.5-34.8Wo39.2-41.4), N=6; diogenitic orthopyroxene: Fs23.5±4.8Wo2.7±1.3 (Fs14.2-28.2Wo0.3-3.8, FeO/MnO=24.4-32.4), N=6; olivine (Fa43.5±6.5, FeO/MnO=50.0-65.3), N=3; plagioclase An92.0±2.1 (An88.5-94.3), N=10.

Classification: Textural and compositional data (Fe/Mn of pyroxenes) indicate this is an HED achondrite. Sample contains 6% diogenite indicating this is a polymict eucrite breccia. The distinctive granular exterior and magnetic susceptibility suggest these stones are paired.

Specimens: John Sinclair holds the remainder of this material. A polished thin section, epoxy mount and 2 slices weighing 41.5 g are on deposit at App.

Data from:
  MB107
  Table 0
  Line 0:
Place of purchase:Tucson Gem and Mineral Show
Date:P 2017
Mass (g):1024
Pieces:34
Class:Eucrite-pmict
Shock stage:moderate
Weathering grade:low
Fayalite (mol%):43.5±6.5
Ferrosilite (mol%):51.4±9.8; 26.2±5.8; 23.5±4.8
Wollastonite (mol%):5.8±2.3; 40.5±0.9; 2.7±1.3
Magnetic suscept.:3.44
Classifier:A. Love, App
Type spec mass (g):41.5
Type spec location:App
Main mass:J. Sinclair
Finder:Unknown
Comments:Submitted by Anthony Love
Institutions
   and collections
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. 107, in preparation (2018)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 6559 approved meteorites from (Northwest Africa) (plus 2021 unapproved names)

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