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Northwest Africa 4721
Basic information Name: Northwest Africa 4721
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 4721
Observed fall: No
Year found: 2005
Country: (Northwest Africa)
Mass:help 7.3 g
Meteoritical Bulletin:  MB 93  (2008)  CK4
Recommended:  CK4    [explanation]

This is 1 of 126 approved meteorites classified as CK4.   [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (equilibrated), CK chondrites, CK chondrites (type 4-6), and CV-CK clan chondrites
Comments: Approved 26 Feb 2008
Revised 4 Aug 2008: final writeup
Writeup from MB 93:

Northwest Africa 4721

Northwest Africa

Find: February 3, 2005

Carbonaceous chondrite (CK4)

History: A single stone was purchased at Tucson Gem and Mineral Show from a Moroccan mineral dealer on February 3, 2005.

Physical characteristics: One stone of 7.3 g. Dark gray stone partly covered with black fusion crust.

Petrography: (K. Yamada and M. Kimura, Ibaraki) Consists of several porphyritic chondrule remnants (up to ~1 mm in diameter), mineral fragments including abundant magnetite, and recrystallized fine-grained matrix; olivine (Fa25-30; average 27.1; NiO up to 0.7 wt%), low-Ca pyroxene (Fs23-28Wo0.3-7; average 24.6 and 1.5); Ca pyroxene (Fs8-15Wo32-48; average 10.0 and 43.7); plagioclase (An16-66Or0.7-4; average 34.9 and 2.3); magnetite (Cr2O3 up to 3.5% and Al2O3 up to 1.7% wt%).

Classification: Carbonaceous chondrite (CK4); S2, moderate weathering.

Type specimens: A total of 1.53 g of sample on deposit at NUM. Hori holds the main mass.

Submitted by: M. Kimura, Ibaraki.

Data from:
  Table 2
  Line 100:
Place of purchase:Tucson, AZ, USA
Date:3 February 2005
Mass (g):7.3
Shock stage:S2
Weathering grade:W2
Fayalite (mol%):25-30 (ave. 27)
Ferrosilite (mol%):23-28 (ave.2 5)
Wollastonite (mol%):0-7
Type spec mass (g):1.53
   and collections
NUM: Nagoya University Museum???, Japan (institutional address; updated 3 Mar 2011)
Ibaraki: Department of Materials and Biological Sciences, Institute of Astrophysics and Planetary Science, Ibaraki University, 2-1-1 Bunkyo, Mito 310-8512, Japan (institutional address; updated 27 Feb 2011)
Hori: Unknown person (private address; updated 17 Apr 2009)
References: Published in Meteoritical Bulletin, no. 93, MAPS 43, 571-632 (2008)
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     This is 1 of 9429 approved meteorites from (Northwest Africa) (plus 1876 unapproved names)

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