Meteoritical Bulletin: Entry for Northwest Africa 12778

header

MetSoc Home Publications Contacts

Search the Meteoritical Bulletin Database
Last update: 15 Apr 2024
Search for:	Search type:	Search limits:	Display:	Publication:
Names Text Places Classes Years	Contains Starts with Exact Sounds like	NonAntarctic Falls Non-NWAs Has strewnfield		What's new in the last:
Include past classifications in search		Has photo	Limit to approved meteorite names
Search text:

Northwest Africa 12778

Basic information

Name: Northwest Africa 12778
This is an OFFICIAL meteorite name.
Abbreviation: NWA 12778
Observed fall: No
Year found: 2018
Country: (Northwest Africa)
Mass: 35.8 g

Classification
history:

Meteoritical Bulletin:	MB 108	(2020)	CM2
Recommended:			CM2 [explanation]

This is 1 of 636 approved meteorites classified as CM2. [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 2), CM chondrites, and CM-CO clan chondrites

Comments:

Approved 26 Sep 2019

Writeup

help

Writeup from MB 108:

Northwest Africa 12778 (NWA 12778)

(Northwest Africa)

Purchased: 2018

Classification: Carbonaceous chondrite (CM2)

History: Purchased by Matthew Stream from Mike Bandli in 2018, who purchased it from Aziz Habibi at the 2018 Tucson Gem and Mineral Show.

Physical characteristics: Four dark-gray stones. A slice reveals a dark fine-grained interior.

Petrography: (D. Sheikh, FSU) Small chondrules present (mean diameter ~260 µm), isolated mineral fragments (Olivine, low-Ca pyroxene, high Ca-Pyroxene) and small CAIs with fine-grained dust rims set in a dark, abundant matrix. In many chondrules the mesostasis has been aqueously altered to phyllosilicates. The matrix also contains phyllosyllicates as indicated by low microprobe totals.

Geochemistry: (D. Sheikh, FSU) Olivine (Fa_11.9±17.0, range Fa_0.7-41.4, Cr₂O₃=0.40±0.13, n=12); low-Ca Pyroxene (Fs_3.5±3.3Wo_0.8±0.3, range Fs_1.1-5.9Wo_0.6-1.0, n=10). Isolated mineral grains of low-Ca Pyroxene (Fs_27.8±1.1Wo_0.5±0.1, range Fs_26.9-29.0Wo_0.4-0.6, n=3) and high-Ca Pyroxene (Fs_9.9Wo_9.2, n=1) found in matrix.

Classification: Carbonaceous Chondrite (CM2)

Specimens: 7.22 grams at UCLA; main mass with Matthew Stream.

Data from:
  MB108
  Table 0
  Line 0:

Place of purchase:	Tucson
Date:	P 2018
Mass (g):	35.8
Pieces:	4
Class:	CM2
Shock stage:	low
Weathering grade:	low
Fayalite (mol%):	11.9±17.0 (0.7-41.4, n=12)
Ferrosilite (mol%):	3.5±3.3 (1.1-5.9, n=10)
Wollastonite (mol%):	0.8±0.3 (0.6-1.0, n=10)
Classifier:	D. Sheikh, FSU
Type spec mass (g):	7.22
Type spec location:	UCLA
Main mass:	Matthew Stream
Comments:	Submitted by Daniel Sheikh

Institutions
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)

Catalogs:

References:

Published in Meteoritical Bulletin, no. 108 (2020) Meteorit. Planet. Sci. 55, 1146-1150

Find references in NASA ADS:
Find references in Google Scholar:

Photos:

Credit	Photos
Public domain photographs:
Daniel Sheikh

Geography:

Coordinates:

Unknown.

Statistics:
This is 1 of 9699 approved meteorites from (Northwest Africa) (plus 1854 unapproved names)

Also see:

This lists the most popular meteorites among people who looked up this meteorite.

Revision
history:

This lists important revisions made to data for this record.

Direct link to this page