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Northwest Africa 6580
Basic information Name: Northwest Africa 6580
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 6580
Observed fall: No
Year found: 2005
Country: (Northwest Africa)
Mass:help 105 g
Classification
  history:
Meteoritical Bulletin:  MB 99  (2011)  L-melt breccia
Recommended:  L-melt breccia    [explanation]

This is 1 of 28 approved meteorites classified as L-melt breccia.   [show all]
Search for other: L chondrites, L chondrites (type 4-7), Melted chondrites, Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 27 Mar 2011
Writeuphelp
Writeup from MB 99:

Northwest Africa 6580 (NWA 6580)

(Northwest Africa)

Purchased: October, 2005

Classification: Ordinary chondrite (L, melt breccia)

History: A portion of the sample was donated to Cascadia on December 13, 2005

Physical characteristics: The single stone is largely covered by a brown-black fusion crust that has prominent shrinkage cracks.

Petrography: (A.Ruzicka and K. Hauver, Cascadia) The main lithology is nearly devoid of opaque minerals and consists largely of fine-grained (~50-100 μm) euhedral to subhedral olivine set in glass; this lithology is in sharp contact with a small area (~9 mm) at the edge of the stone that shows chondritic texture.

Geochemistry: Mineral compositions and geochemistry: Fine-grained portion has olivine Fa 18.8±6.9 (n=11); chondritic portion has olivine Fa 22.8±3.4, median 24.1 (n=24); kamacite Ni 4.78±1.55 wt% and Co 0.89±0.14 wt% (n=19); martensite Ni 13.4±4.3 wt% and Co 0.64±0.13 wt% (n=12).

Classification: Ordinary chondrite melt-breccia. Olivine Fa and kamacite Co contents from the chondritic portion are similar to L chondrites, and martensite composition is similar to the bulk composition of metal in L chondrites.

Specimens: Type specimens available at Cascadia include 1 piece originally 20.0 g, from which one polished thin section and one polished butt were made. Thompson holds the main mass.

Data from:
  MB99
  Table 0
  Line 0:
Place of purchase:Munich, Germany
Date:P October, 2005
Mass (g):105
Pieces:1
Class:L-melt breccia
Shock stage:high
Weathering grade:W1
Fayalite (mol%):24.1
Classifier:A. Ruzicka, K. Hauver
Type spec mass (g):20.0
Type spec location:Cascadia
Main mass:Thompson
Comments:Field number CML0371.; submitted by A. Ruzicka
Institutions
   and collections
Cascadia: Cascadia Meteorite Laboratory, Portland State University, Department of Geology, Room 17 Cramer Hall, 1721 SW Broadway, Portland, OR 97201, United States; Website (institutional address; updated 28 Oct 2011)
Thompson: Edwin Thompson, 5150 Dawn St., Lake Oswego, OR 97035, United States (private 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:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 6984 approved meteorites from (Northwest Africa) (plus 2008 unapproved names)

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