MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 20 Jun 2022
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 12904
Basic information Name: Northwest Africa 12904
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12904
Observed fall: No
Year found: 2018
Country: Morocco
Mass:help 71.1 g
Meteoritical Bulletin:  MB 108  (2020)  LL4-5
Recommended:  LL4-5    [explanation]

This is 1 of 15 approved meteorites classified as LL4-5.   [show all]
Search for other: LL chondrites, LL chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 21 Sep 2019
Writeup from MB 108:

Northwest Africa 12904 (NWA 12904)


Purchased: 2018

Classification: Ordinary chondrite (LL4-5)

History: Purchased by Matthew Stream at the 2018 Tucson Gem Show in Tucson, AZ.

Physical characteristics: Single stone with dark-brown fusion crust.

Petrography: (Daniel Sheikh, FSU) Low chondrule abundance (900±100 µm, n=4). Sample composed of both type 4 and type 5 clasts present in a dark, fine-grained matrix. Major phases present include olivine, low-ca pyroxene, high-ca pyroxene, recrystallized sodic plagioclase (only in type 5 clasts, average size 5 µm), troilite, Fe-Ni metal, and chromite.

Geochemistry: Olivine (Fa30.6±0.8, n=40), Low-Ca Pyroxene (Fs25.5±0.6 Wo1.8±0.5, n=5), High-Ca Pyroxene (Fs10.5±0.5 Wo43.2±0.3, n=4), Sodic Plagioclase (An12.4±0.3, n=4).

Classification: Ordinary Chondrite (LL4-5) Sample is classified as type 4-5 due to the homogeneity of the olivine and pyroxene grains and the absence of recrystallized plagioclase in the type 4 clasts as well as the homogeneity of the olivine and pyroxene grains and the presence of 5 µm recrystallized plagioclase in the type 5 clasts.

Specimens: 14.94 grams at UCLA; main mass with Matthew Stream.

Data from:
  Table 0
  Line 0:
Place of purchase:Tucson, AZ
Date:P 2018
Mass (g):71.09
Shock stage:S3
Weathering grade:W2
Fayalite (mol%):30.6±0.8
Ferrosilite (mol%):25.5±0.6
Wollastonite (mol%):1.8±0.5
Classifier:Daniel Sheikh, Florida State University
Type spec mass (g):14.94
Type spec location:UCLA
Main mass:Matthew Stream
Comments:Submitted by Daniel Sheikh
   and collections
UCLA: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095-1567, United States (institutional address; updated 17 Oct 2011)
FSU: Department of Geological Sciences, Florida State University, Tallahassee FL 32306-4100, United States (institutional address; updated 16 Dec 2010)
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 1847 approved meteorites from Morocco (plus 24 unapproved names) (plus 1 impact crater)

Direct link to this page