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Northwest Africa 5644
Basic information Name: Northwest Africa 5644
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 5644
Observed fall: No
Year found: 2008
Country: (Northwest Africa)
Mass:help 200 g
Classification
  history:
Meteoritical Bulletin:  MB 99  (2011)  Achondrite-ung
Recommended:  Achondrite-ung    [explanation]

This is 1 of 86 approved meteorites classified as Achondrite-ung.   [show all]
Search for other: Achondrites, Ungrouped achondrites
Comments: Approved 2 Sep 2010
Writeuphelp
Writeup from MB 99:

Northwest Africa 5644 (NWA 5644)

(Northwest Africa)

Purchased: Nov 2008

Classification: Ungrouped achondrite

History: Purchased in Erfoud, Morocco, in November, 2008.

Physical characteristics: A light tan to rusty brown, angular single stone devoid of fusion crust, with a total mass of 200 g.

Petrography (Albert Jambon, Omar Boudouma and Dominique Badia, UPVI):  One polished section of about one cm2 was studied by EMPA and SEM. The rock is medium grained, composed of light-brown pyroxene (0.2 to 1 mm) and interstitial mm-sized aggregates of plagioclase (0.01 to 0.05 mm) with lobate boundaries against pyroxene, sometimes with poikilitic pyroxene. Clusters of opaques up to several mm are conspicuous on both the sawn and altered surfaces, with poikilitic pyroxene, plagioclase and silica. Rims of Fe-rich olivine occur around pyroxene against ilmenite and spinel. Modes from BSE images (vol%) are: plagioclase 39, pyroxene 54. silica 2, fayalite 1, opaques 3. Contains minor troilite and rare pentlandite. Kamacite and taenite are partly oxidized.

Geochemistry: Pyroxene exhibits well-developed exsolution bands of augite (En25Fs32Wo42) and pigeonite (En31Fs63Wo6), but all intermediate compositions are present. The FeO/MnO ratio (73±7) is identical for augite and pigeonite, and distinctly higher than the HED range. Plagioclase is An82-93. Minor phases are spinel (Us64Ct24), ilmenite, olivine (Fa80), metal with up to 55% Ni and badly oxidized, pentlandite and silica. Shock is moderate and, with the exception of the oxidation of metal and sulfide, weathering effects are moderate.

Classification: In its texture, mineral mode and mineral compositions this rock is nearly identical to the achondrite NWA 011, which strongly suggests that these two stones are paired.

Specimens: 21 g and one polished section are on deposit at UPVI. A. Habibi holds the main mass.

Data from:
  MB99
  Table 0
  Line 0:
Place of purchase:Erfoud, Morocco
Date:P Nov 2008
Mass (g):200
Pieces:1
Class:Achondrite-ung
Ferrosilite (mol%):32
Wollastonite (mol%):42
Classifier:Albert Jambon , Omar Boudouma and Dominique Badia
Type spec mass (g):21
Type spec location:UPVI
Main mass:Habibi
Comments:Submitted by Albert Jambon
Institutions
   and collections
UPVI: Université Pierre et Marie Curie (Paris VI),Case 110, 4 Place Jussieu, 75005 Paris, France (institutional address; updated 5 Oct 2014)
Catalogs:
References: Published in Meteoritical Bulletin, No. 99, April 2012, MAPS 47, E1-E52 (2012) [published online only]
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 6900 approved meteorites from (Northwest Africa) (plus 2027 unapproved names)

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