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Northwest Africa 12205
Basic information Name: Northwest Africa 12205
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12205
Observed fall: No
Year found: 2013
Country: (Northwest Africa)
Mass:help 144.9 g
Meteoritical Bulletin:  MB 108  (2020)  Ureilite
Recommended:  Ureilite    [explanation]

This is 1 of 630 approved meteorites classified as Ureilite.   [show all]
Search for other: Achondrites, Ureilites
Comments: Approved 7 Mar 2019
Writeup from MB 108:

Northwest Africa 12205 (NWA 12205)

(Northwest Africa)

Purchased: 2013 Feb

Classification: Ureilite

Physical characteristics: Puck-shaped, dark-brown stone with remnant fusion crust on approx. half the surface. Remaining surface is broken with minor caliche and rust spots in some areas. Sample includes a polished thin section and billet.

Petrography: Sample is characterized by a lack of a reduction rim around olivine, as well as abundant low-Ca pyroxene. Triple junctions are observed throught the sample and an opaque phase interfills 100-200 μm silicates. Low-Ca pyroxenes form 3 mm sized aggregates. Porphyroblastic Ca-rich pyroxene is present. Modal abundances: olivine approx. 60%; low-Ca pyroxenes approx. 30%; remainder is opaque material.

Geochemistry: Olivine core: Fa12.4±0.1 FeO/MnO = 21.88±1.38 (n=6). Augite: Fs6.6±0.2Wo36.9±0.2, (n=8). Pigeonite: Fs10.9±0.1Wo4.7±0.1, (n=4). δ17O = 3.771 permil, δ18O = 8.206 permil, Δ17O = -0.877 permil.

Data from:
  Table 0
  Line 0:
Place of purchase:Tucson Gem and Mineral Show
Date:P 2013 Feb
Mass (g):144.86
Fayalite (mol%):12.4±0.09
Ferrosilite (mol%):6.6±0.2; 10.9±0.1
Wollastonite (mol%):36.9±0.2; 4.7±0.1
Classifier:T. Kunihiro, E. Nakamura, T. Ota, R. Tanaka OkaU
Type spec mass (g):23.87
Type spec location:ROM
Main mass:DGregory
Comments:Registered at ROM as M58177. Studied at OkaU as TSE-URE-M58177(R0); submitted by V. Di Cecco, ROM
Plots: O isotopes:  
   and collections
ROM: Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2C6, Canada (institutional address; updated 18 Oct 2011)
DGregory: David Gregory, 230 First Avenue, Suite 108, St. Thomas, Ontario N5R 4P5, Canada (private address)
OkaU: Institute for Study of the Earth's Interior, Okayama University, Misasa Tottori 682-0193, Japan (institutional address)
References: Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
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     This is 1 of 9116 approved meteorites from (Northwest Africa) (plus 1873 unapproved names)

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