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Northwest Africa 8659
Basic information Name: Northwest Africa 8659
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 8659
Observed fall: No
Year found: 2013
Country: (Northwest Africa)
Mass:help 45.8 g
Classification
  history:
Meteoritical Bulletin:  MB 104  (2015)  Eucrite
Recommended:  Eucrite    [explanation]

This is 1 of 431 approved meteorites (plus 1 unapproved name) classified as Eucrite.   [show all]
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 18 Feb 2015
Writeuphelp
Writeup from MB 104:

Northwest Africa 8659 (NWA 8659)

(Northwest Africa)

Purchased: Oct 2013

Classification: HED achondrite (Eucrite)

History: The meteorite was found as a single mass of 45.8 g in 2013 by an anonymous searcher, and was purchased by A. Jonikas in Dec 2013.

Physical characteristics: The stone has a distinct dark crust, but this appears to be almost entirely desert varnish, not fusion crust.

Petrography: (P. Warren, UCLA) Slices through the stone indicate that most of the material is thoroughly brecciated, yet a single large clast comprising about 40% of the stone is essentially unbrecciated. The unbrecciated material shows a subopthitic texture with grain size typically 2 mm. Minor Fe-metal. The pyroxernes are to an unusual extent pervaded by secondary olivine-dominated veins.

Geochemistry: Pyroxene is mostly equilibrated to a tie-line between low-Ca pyroxene En32.0±0.7Wo3.4±0.4, FeO/MnO wt ratio 33.6±1.5, n=11, and high-Ca pyroxene En26.6±0.1Wo42.3±0.2, n=6, but in the cores of a few large grains a low-Ca zoning trend survives with composition as magnesian as En58Wo7; primary-igneous plagioclase An81.3±2.4, n=40; secondary veins within pyroxenes have An98 plagioclase, along with olivine Fa83.5±0.5, n=11. Oxygen isotopes: (I. Kohl and E. Young, UCLA) δ17O 2.083, δ18O 4.376, Δ17O -0.227 (all normalized). Bulk composition: (fused-bead EPMA, in wt%, derived from a 0.28 g powder) SiO2 49.5, TiO2 1.28, Al2O3 11.5, Cr2O3 0.24, MgO 5.5, FeO 18.2, MnO 0.51; mg# 0.349.

Classification: Eucrite (monomict-brecciated). Unusually ferroan, Ti-rich, and rich in secondary metasomatic veins.

Specimens: The main mass, 34 g, is held by Aras Jonikas.

Data from:
  MB104
  Table 0
  Line 0:
Place of purchase:Morocco
Date:P Oct 2013
Mass (g):45.8
Pieces:1
Class:Eucrite
Shock stage:moderate
Weathering grade:moderate
Fayalite (mol%):84
Ferrosilite (mol%):64.6
Wollastonite (mol%):3.4
Classifier:P. Warren, UCLA
Type spec mass (g):11.56
Type spec location:UCLA
Main mass:A. Jonikas
Comments:Submitted by P. Warren
Plots: O isotopes:  
Institutions
   and collections
UCLA: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095-1567, United States (institutional address; updated 17 Oct 2011)
Catalogs:
References: Published in Meteoritical Bulletin, no. 104, MAPS 52, 2284, Octover 2017, http://onlinelibrary.wiley.com/doi/10.1111/maps.12930/full
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 2035 unapproved names)

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