MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 29 Jan 2023
Search for: Search type: Search limits: Display: Publication:
Text help
Starts with
Sounds like
Falls  Non-NWAs
What's new
  in the last:
Include past classifications in search
Limit to approved meteorite names
Search text:  
Northwest Africa 12866
Basic information Name: Northwest Africa 12866
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12866
Observed fall: No
Year found: 2013
Country: Morocco
Mass:help 191 g
Meteoritical Bulletin:  MB 108  (2020)  Eucrite
Recommended:  Eucrite    [explanation]

This is 1 of 569 approved meteorites (plus 1 unapproved name) classified as Eucrite.   [show all]
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 11 Oct 2019
Writeup from MB 108:

Northwest Africa 12866 (NWA 12866)


Purchased: September 2013

Classification: HED achondrite (Eucrite)

History: Sample number (LM58159) in the Royal Ontario Museum collection.

Physical characteristics: A single angular stone partially covered with a black shiny fusion crust. The cut stone shows a fresh grey surface.

Petrography: The thin section shows a complex polymict breccia, consisting of mineral clasts and large rock fragments of up to 2 cm long, embedded within a fine-grained clastic matrix. Rock fragments are composed of fine- and medium-grained pyroxene and plagioclase of granular and gabbroic texture. Both high-Ca exsolved augite and pigeonite is present; both show little to no mosaicism; augite lamellae are locally displaced by low shock. Plagioclase is relatively fresh and no maskelynite is present. Minor minerals are ilmenite, chromite, tridymite, quartz, apatite, merrillite, zircon and FeNi metal.

Geochemistry: Mineral compositions and geochemistry: Ferrosilite (Wo1.2-4.5En32.1-42.7 Fs55.9-66.5; FeO/MnO=29.9-32.5) with Pigeonite lamellae (Wo5.2-18.2En32.3-41.5Fs48.3-61.3; FeO/MnO=30.9-32.2), pigeonite (Wo6.1-10En27.1-32.4Fs57.5-63.9; FeO/MnO=29.9-32.5) with augite lamellae (Wo22.4-32.6En27.8-37.3Fs31.5-49.6;FeO/MnO=29.4-32.2). Plagioclase ranges from An72-90 with an average of An81.

Classification: Eucrite (polymict breccia)

Data from:
  Table 0
  Line 0:
Place of purchase:Denver Gem and Mineral Show
Date:P September 2013
Mass (g):191.04
Shock stage:low
Weathering grade:low
Ferrosilite (mol%):44.1±10.7 (N=9); 58.3±10.9 (N=16)
Wollastonite (mol%):25±6.4 (N=9); 6.6±9.2 (N=16)
Classifier:B. Rider-Stokes, UPort
Type spec mass (g):21.05
Type spec location:ROM
Main mass:ROM
Comments:Submitted by V. Di Cecco (ROM)
   and collections
ROM: Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2C6, Canada (institutional address; updated 18 Oct 2011)
UPort: University of Portsmouth Winston Churchill Avenue Portsmouth, Hampshire PO1 2UP, United Kingdom (institutional address; updated 11 Oct 2019)
References: Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150
Find references in NASA ADS:
Find references in Google Scholar:


     This is 1 of 1932 approved meteorites from Morocco (plus 27 unapproved names) (plus 1 impact crater)

Direct link to this page