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Northwest Africa 10918
Basic information Name: Northwest Africa 10918
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 10918
Observed fall: No
Year found: 2013
Country: (Northwest Africa)
Mass:help 61.9 g
Classification
  history:
Meteoritical Bulletin:  MB 105  (2016)  CV3
Recommended:  CV3    [explanation]

This is 1 of 536 approved meteorites (plus 1 unapproved name) classified as CV3.   [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 3), CV chondrites, and CV-CK clan chondrites
Comments: Approved 3 Dec 2016
Writeuphelp
Writeup from MB 105:

Northwest Africa 10918 (NWA 10918)

(Northwest Africa)

Purchased: 2013

Classification: Carbonaceous chondrite (CV3)

History: A meteorite was purchased by Mike Miller in 2013 at the Tucson Gem and Mineral Show and subsequently acquired by the Center for Meteorite Studies, ASU.

Physical characteristics: A single 61.86 g angular stone with shiny black (possibly sand-blasted) exterior; chondrules and CAIs visible on the surface. Sawn surface is orange stained, and shows an abundance of chondrules and CAIs set in a dark matrix.

Petrography: (E. Dunham and J. Zalesky, ASU) In a 2 × 3 cm section, there are ~80 chondrules (average 1.2 mm n=20, largest ~ 3 mm), and four CAIs (to ~ 1 cm in diameter), set in a dark, fine-grained matrix that accounts for ~32% of the section. Chondrules are predominantly POP, and a few BO, PP, and olivine fragments. Some chondrules are surrounded by a rim of FeS and weathered metal. Mesostasis rare within chondrules, but where present consists of anorthite (An93). Most chondrules have an irregular outline, but the boundary between them and matrix is distinct. The thin section contains a Type B CAI composed of melilite, pyroxene, and spinel surrounded by rim of pyroxene and hibonite, and a compact Type A (CTA) CAI dominated by coarse melilite with small perovskite blebs and surrounded by a <50 μm rim including pyroxene, and a very fine-grained object (possibly a CAI). The shock grade is low and weathering high.

Geochemistry: The compositional range for olivine in chondrules is Fa0.7±0.3, 0.3-1.4 (Cr2O3 = 0.08-0.51 wt.%). Olivine phenocrysts from nine POP chondrules is Fa0.3-1, and olivine phenocrysts from one intact PO chondrule is Fa0.8-1.4. The POP chondrules contain pyroxene with a compositional range Fs46±6.8Wo72.2±24.0 (Fa0.2-23Wo38-97). The Type B CAI is composed of Al-rich melilite and pyroxene Fs3.6±2.3Wo64.2±8.3 (Fs0.5-5Wo47-67). The CTA CAI is primarily composed of melilite Ak~5-15 with a rim of Ca- Ti- rich pyroxene Fs0.6-1.8Wo62-64.

Classification: Carbonaceous chondrite CV3, high weathering, low shock.

Specimens: One polished thin section, two thick sections, the main mass is held by ASU

Data from:
  MB105
  Table 0
  Line 0:
Place of purchase:Tucson
Date:P 2013
Mass (g):61.9
Pieces:1
Class:CV3
Shock stage:low
Weathering grade:high
Fayalite (mol%):0.73±0.32
Classifier:E. Dunham, J. Zalesky, ASU
Type spec mass (g):61.9
Type spec location:ASU
Main mass:ASU
Finder:anonymous
Comments:ASU#1902; submitted by L. Garvie
Institutions
   and collections
ASU: Center for Meteorite Studies, Arizona State University, Tempe, Arizona 85287-1404, United States; Website (institutional address; updated 14 Jan 2012)
Catalogs:
References: Published in Meteoritical Bulletin, no. 105, MAPS 52, 2411, September 2017. http://onlinelibrary.wiley.com/doi/10.1111/maps.12944/full
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7328 approved meteorites from (Northwest Africa) (plus 1973 unapproved names)

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