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Northwest Africa 14991
Basic information Name: Northwest Africa 14991
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 14991
Observed fall: No
Year found: 2021
Country: (Northwest Africa)
Mass:help 54 g
Classification
  history:
Recommended:  CM2    [explanation]

This is 1 of 614 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 20 Jun 2022
Writeuphelp
Writeup from MB 111:

Northwest Africa 14991 (NWA 14991)

(Northwest Africa)

Purchased: 2021

Classification: Carbonaceous chondrite (CM2)

History: Purchased by Ziyao Wang in Algeria from a meteorite dealer in May 2021.

Physical characteristics: Many identically appearing pieces. Dark fusion-crusted exterior, broken surface reveals numerous small chondrules set in a dark gray matrix that makes up over 50% of this meteorite. Small CAIs are visible.

Petrography: (A. Ross and C. Agee, UNM) Microprobe and reflected light microscopy examination reveal a fine-grained matrix that gives low microprobe totals from the presence of hydrous phases. Many chondrules are porphyritic type I with predominantly forsteritic olivines. Matrix olivines are mostly fragmental and ferroan. Apparent mean chondrule diameter approximately 300 μm. Aluminous diopside, calcite, troilite, Fe-Ni sulfide, and low-Ni iron metal were detected.

Geochemistry: (A. Ross and C. Agee, UNM) Type I chondrule olivine Fa1.2±1.0, Cr2O3=0.44±0.11 (wt%) n=8; ferroan matrix olivine Fa29.2±15.0, Fe/Mn=82±20, Cr2O3=0.29±0.10 (wt%) n=7; low-Ca pyroxene Fs7.5±10.6Wo2.1±2.1, n=6; matrix (20 μm defocused microprobe beam) analytical totals of 76.0±3.3 wt% and FeO=34.1±5.6 wt%, n=3.

Classification: Carbonaceous chondrite (CM2). The low analytical totals in the matrix indicate the presence of hydrous phases.

Specimens: 12 g on deposit at UNM, WangZ holds the main mass.

Data from:
  MB111
  Table 0
  Line 0:
Place of purchase:Algeria
Date:P 2021
Mass (g):54
Pieces:Many
Class:CM2
Shock stage:low
Weathering grade:low
Fayalite (mol%):1.2±1.0, 29.2±15.0
Ferrosilite (mol%):7.5±10.6
Wollastonite (mol%):2.1±2.1
Classifier:C. Agee, UNM
Type spec mass (g):12
Type spec location:UNM
Main mass:WangZ
Comments:WZY-07; submitted by C. Agee
Institutions
   and collections
UNM: Institute of Meteoritics MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 USA, United States; Website (institutional address; updated 12 Feb 2015)
WangZ: Ziyao Wang, Hebei GEO University North Campus, Huai An dong road 127, Shijiazhuang, Hebei Province , China (private address; updated 25 Jun 2021)
Catalogs:
References: Published in Meteoritical Bulletin, no. 111, in preparation (2022)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 8745 approved meteorites from (Northwest Africa) (plus 1880 unapproved names)

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