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Northwest Africa 12636
Basic information Name: Northwest Africa 12636
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12636
Observed fall: No
Year found: 2018
Country: (Northwest Africa)
Mass:help 967 g
Meteoritical Bulletin:  MB 108  (2020)  Diogenite
Recommended:  Diogenite    [explanation]

This is 1 of 511 approved meteorites classified as Diogenite.   [show all]
Search for other: Achondrites, Diogenites, and HED achondrites
Comments: Approved 3 Jun 2019
Writeup from MB 108:

Northwest Africa 12636 (NWA 12636)

Northwest Africa

Purchased: 2018

Classification: HED achondrite (Diogenite)

History: One stone weighing 967 g was found in Morocco prior to 2018. Blaine Reed purchased the sample from a meteorite dealer while at the 2018 Tucson Gem and Mineral Show.

Physical characteristics: The sample has a yellowish-brown exterior with a few small patches of black fusion crust. The sample has yellowish-orange interior that is brecciated and friable. The cut face shows angular-subrounded clasts up to 1.5cm in long dimension.

Petrography: Description and classification (A. Love, App): Sample is a breccia composed of diogenitic lithic fragments and coarser grained cataclastic clasts mixed within a comminuted host of similar materials. Lithic clasts are composed of interlocking, orthopyroxenes which share 120º grain boundaries. Orthopyroxenes contain Cpx inclusions and exsolution lamellae (up to 0.5µm) within crystals. Additional minerals are silica polymorphs, hercynitic chromite, FeS, and rare Ni-free iron metal. Orthopyroxenes within some lithic clasts exhibit normal extinction and equilibrium textures.

Geochemistry: (A. Love, App) low Ca pyroxene: Fs27.2±0.6Wo1.5±0.1, Fe/Mn=26.6±0.6, n=14; high Ca pyroxene Fs10.5±0.4Wo44.9±0.5, Fe/Mn=22.5±1.1,n=4.

Classification: Monomict diogenite breccia. Fe/Mn compositions of pyroxenes indicate this sample is diogenite meteorite. Textures and Fs compositions of pyroxenes indicate this sample is a diogenite.

Specimens: Blaine Reed holds the main mass. Two slices weighing 28.13 g and a polished mount are on deposit at App.

Data from:
  Table 0
  Line 0:
Place of purchase:Tucson Gem and Mineral Show
Date:P 2018
Mass (g):967
Shock stage:low
Weathering grade:low
Ferrosilite (mol%):27.2±0.6;10.5±0.4
Wollastonite (mol%):2.7±0.6;44.9±0.5
Classifier:A. Love, App
Type spec mass (g):28.13
Type spec location:App
Main mass:Blaine Reed
Comments:Submitted by Anthony Love
   and collections
App: Department of Geology, 572 Rivers St., Appalachian State University, Boone, NC 28608, United States (institutional address; updated 7 Mar 2013)
Reed: Blaine Reed, P.O. Box 1141, Delta, CO 81416, United States; Website (private address)
References: Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
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Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
Ryan Upchurch   

     This is 1 of 9116 approved meteorites from (Northwest Africa) (plus 1873 unapproved names)

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