header
  MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 11 Oct 2019
Search for: Search type: Search limits: Display: Publication:
Names
Text help
Places
Classes
Years
Contains
Starts with
Exact
Sounds like
NonAntarctic
Falls  Non-NWAs
What's new
  in the last:
Limit to approved meteorite names
Search text:  
Northwest Africa 12750
Basic information Name: Northwest Africa 12750
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 12750
Observed fall: No
Year found: 2019
Country: (Northwest Africa)
Mass:help 46 g
Classification
  history:
Recommended:  CO3    [explanation]

This is 1 of 522 approved meteorites classified as CO3.   [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 3), CM-CO clan chondrites, and CO chondrites
Comments: Approved 6 Oct 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 12750 (NWA 12750)

(Northwest Africa)

Purchased: 2019

Classification: Carbonaceous chondrite (CO3)

History: A 46 g stone, comprising 3 pieces that fit together, was found in the Western Sahara prior to 2018. The sample was sold to a meteorite dealer and subsequently purchased during the 2019 Tucson Gem and Mineral Show.

Physical characteristics: The sample lacks fusion crust, is dark brown in color and irregularly shaped. Small chondrules are visible on the surface. Small chondrules and CAIs are visible on the cut face.

Petrography: (A. Love, App): Sample has a chondritic texture composed of chondrules with an average diameter of 150 μm (N=57), abundant amoeboid olivine aggregates and CAIs set within a fine-grained opaque matrix (~36 vol%).

Geochemistry: (A. Love, App) Olivine: Fa19.4±20.4(Fa0.4-64.4), Fe/Mn=60.1±43.3), N=32 chondrules (14 Type I chondrules with Fa0.92±0.40, and 18 Type II chondrules with Fa33.8±16.0). Cr2O3 in ferroan olivine = 0.3±0.1, N=18. Low Ca pyroxene: Fs4.1±3.3Wo1.0±0.7 (Fs1.3-12.5Wo0.3-2.8), N=15.

Classification: Carbonaceous Chondrite (CO3). Based on chondrule size and unequilibrated compositions of olivine and pyroxene, sample is a type 3 CO chondrite. Mean and standard deviation of Cr2O3 in ferroan olivine plots next to Acfer 094 designated by Grossman and Brearley (2005) as CO3.0

Specimens: The main mass is held at PARI. An 9.3 g fragment and a polished thin section are on deposit at App.

Bibliography:
  • Grossman J.N. and Brearley A.J. (2005) The onset of metamorphism in ordinary and carbonaceous chondrites. Meteorit. Planet. Sci. 40, 87-122. (link)
Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Tucson Gem and Mineral Show
Date:P 2019
Mass (g):46
Pieces:3
Class:CO3
Shock stage:C-S1
Weathering grade:low
Fayalite (mol%):25.7±20
Ferrosilite (mol%):4.1±3.3
Wollastonite (mol%):1.0±0.7
Magnetic suscept.:4.59
Classifier:A. Love, App
Type spec mass (g):9.3
Type spec location:App
Main mass:PARI
Finder:Unknown
Comments:Submitted by Anthony Love
Institutions
   and collections
App: Department of Geology, 572 Rivers St., Appalachian State University, Boone, NC 28608, United States (institutional address; updated 7 Mar 2013)
PARI: Pisgah Astronomical Research Institute 1 Pari Dr Rosman, NC 28772, United States (institutional address; updated 13 Sep 2016)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108, in preparation (2019)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 6968 approved meteorites from (Northwest Africa) (plus 2012 unapproved names)

Direct link to this page