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Northwest Africa 6704
Basic information Name: Northwest Africa 6704
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 6704
Observed fall: No
Year found: unknown
Country: Algeria
Mass:help 8.39 kg
Classification
  history:
Meteoritical Bulletin:  MB 99  (2011)  Achondrite-ung
Recommended:  Achondrite-ung    [explanation]

This is 1 of 82 approved meteorites classified as Achondrite-ung.   [show all]
Search for other: Achondrites, Ungrouped achondrites
Comments: Approved 17 May 2011
Revised 11 Mar 2012: Updated mass
Writeuphelp
Writeup from MB 99:

Northwest Africa 6704 (NWA 6704)

Algeria

Purchased: Jan-May 2011

Classification: Ungrouped achondrite

History: A single, dense, yellowish-green stone was found in pieces in Algeria, and was purchased in February 2011 at the Tucson Gem and Mineral Show and over subsequent weeks from Moroccan dealers by Greg Hupé.

Physical characteristics: The reassembled 42 pieces (plus some granular debris) fit together as a single ovoid mass (8387 g) with rounded, shiny exterior surfaces and small patches of remnant black fusion crust. The very fresh interior is mostly pale yellowish green with sporadic darker brownish grains and sparsely distributed tiny grains of opaque oxide and silvery metal.

Petrography: (A. Irving and S. Kuehner, UWS): Overall medium grained with an igneous cumulate texture. Small grains of olivine (0.5-0.8 mm) and chromite (0.1-0.6 mm) enclosed within large (to 4 mm) orthopyroxene oikocrysts, which are in turn surrounded by large optically continuous, intercumulus grains of untwinned albite and <0.1 mm awaruite. The silicates contain curvilinear trains of tiny rounded inclusions (2-20 μm), which appear on polished surfaces to be empty bubbles with smooth rounded walls.

Geochemistry: Olivine (Fa51.6-53.2; FeO/MnO=120-140; NiO=0.9-1.0 wt.%), orthopyroxene (Fs41.6-42.4Wo2.8-3.6, FeO/MnO=81-82; Cr2O3=0.3 wt.%), plagioclase (Ab92-93An4-3Or4). Oxygen isotopes (R. Tanaka, OkaU): replicate analyses of acid-washed material by laser fluorination gave: δ17O 1.015, 0.880; δ18O 3.922, 3.613; Δ17O -1.048, -1.020 per mil.

Classification: Achondrite (ungrouped). This specimen is unlike other achondrites in its combined features: relatively ferroan mafic silicate minerals with elevated FeO/MnO ratios and anomalous Ni contents, extremely sodic plagioclase, very Ni-rich metal, and oxygen isotopic composition that plots within the field for acapulcoites-lodranites. Weathering is low and limited to minor coatings of pale orange desert dust on broken surfaces. Unshocked.

Specimens: A total of 20.5 g of type material and two polished thin sections are on deposit at UWS. The remaining material is held by GHupé.

Data from:
  MB99
  Table 0
  Line 0:
Place of purchase:Tucson and Morocco
Date:P 2011 Jan-May
Mass (g):8387
Pieces:42
Class:Achondrite-ung
Shock stage:low
Weathering grade:low
Fayalite (mol%):51.6-53.2
Ferrosilite (mol%):41.6-42.4
Wollastonite (mol%):2.8-3.6
Classifier:A. Irving and S. Kuehner, UWS
Type spec mass (g):20.5
Type spec location:UWS
Main mass:G. Hupe
Comments:Submitted by A. Irving
Plots: O isotopes:  
Institutions
   and collections
UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012)
GHupé: Gregory M. Hupé, 9003 Placid Lakes Blvd., Lake Placid, FL 33852, United States; Website (private address)
Hupe: (old address—now see GHupé or AHupé) G. and A. Hupe, 2616 Lake Youngs Court SE, Renton, WA 98058., United States (private address)
OkaU: Institute for Study of the Earth's Interior, Okayama University, Misasa Tottori 682-0193, Japan (institutional address)
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:
Photos:
CreditPhotos
Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
Aeroliths Collection Theodossiou   
aranemac      
bphd   
Christophe PICQ   
Dominik Stoeckli   
Gerald Armstrong   
Gregor H.            
John Lutzon         
Michael S. Scherman   
plagioklas   
Solar Anamnesis   
Public domain photographs:
Tony Irving   
Geography:

Algeria
Coordinates:Unknown.

Statistics:
     This is 1 of 944 approved meteorites from Algeria (plus 26 unapproved names) (plus 4 impact craters)

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