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Northwest Africa 5789
Basic information Name: Northwest Africa 5789
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 5789
Observed fall: No
Year found: unknown
Country: Morocco
Mass:help 49 g
Classification
  history:
Meteoritical Bulletin:  MB 97  (2010)  Shergottite
Recommended:  Martian (shergottite)    [explanation]

This is 1 of 284 approved meteorites (plus 2 unapproved names) classified as Martian (shergottite).   [show all]
Search for other: Martian meteorites
Comments: Approved 10 Dec 2009
Writeuphelp
Writeup from MB 97:

Northwest Africa 5789

Morocco

Find (found January 2009, purchased May 2009)

Achondrite (Martian, olivine-phyric shergottite)

History: A small chip from one of three crusted stones found together in Morocco was sent from a dealer in Erfoud to Greg Hupé , and subjected to preliminary testing at UWS. Subsequently the stones were purchased in May 2009 by Stefan Ralew and Martin Altmann.

Physical characteristics: A 49 g partly crusted stone, naturally broken into three pieces that fit together (Fig. 4a). The interior consists mainly of pale yellowgreen olivine macrocrysts in a light brownish-gray, finer-grained matrix (Fig. 4b). No maskelynite is evident. Several exterior sides are coated by glossy black fusion crust, which contains embedded rounded quartz grains.

Petrography: (A. Irving and S. Kuehner, UWS; J. Gross, A. Treiman, K. Robinson, LPI) Small (up to 1 mm), zoned olivine macrocrysts (in multi-crystalline clusters) with narrow ferroan rims are set in a finer grained groundmass composed mainly of prismatic low-Ca pyroxene grains with accessory olivine, chromite, pyrrhotite, and small regions of mesostasis (approximately 2 vol%) composed of subparallel, laminar to sheaf-like intergrowths of pigeonite, intermediate plagioclase, silica, ilmenite, and merrillite. The pyroxenes exhibit chaotic compositional zoning, with low-Ca pyroxene cores, regions of pigeonite and augite, and narrow ferropigeonite rims.

Geochemistry: Olivine macrocrysts (cores Fa15.6–16.6, FeO⁄MnO = 45.2–49.4; mantle Fa22.6, FeO⁄MnO = 47.6; rim Fa45.4, FeO⁄MnO = 58.9), matrix olivine (Fa47.3, FeO⁄MnO = 61.1), low-Ca pyroxene (cores as magnesian as Fs17.1Wo1.6, FeO⁄MnO = 30.9), pigeonite

Classification: Achondrite (Martian, olivine-phyric shergottite). This specimen has mineralogical and bulk compositional similarities to Yamato 980459980497, but differs from those stones in having very little mesostasis.

Specimens: A total of 9.8 g, two polished thin sections and a polished mount are on deposit at UWS; a further 5.6 g of material is held by A. Treiman (LPI) and another 3.3 g at UAb. The remaining material is held by anonymous collectors and institutions.

Fig. 4. a) A 29.7 g crusted piece of NWA 5789. b) A 1.8 g
fragment showing large olivine grains. Cube for scale is 1 cm.

Data from:
  MB97
  Table 1
  Line 263:
Origin or pseudonym:Morocco
Date:January 2009
Mass (g):49
Pieces:1
Class:Shergottite
Fayalite (mol%):15.6-16.6
Ferrosilite (mol%):17.1
Wollastonite (mol%):1.6
Classifier:A. Irving, S. Kuehner, UWS
Type spec mass (g):9.8+
Type spec location:UWS+
Main mass:Anon
Comments:Olivine-phyric shergottite. See written description
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)
UAb: 1-26 Earth Sciences Building, University of Alberta, Edmonton, AB, T6G 2E3, Canada, Canada; Website (institutional address; updated 17 Oct 2011)
LPI: Lunar and Planetary Institute, 3600 Bay Area Blvd., Houston, TX 77058 , United States; Website (institutional address; updated 20 Jun 2022)
Ralew: Stefan Ralew, Kunibertstraße 29, 12524 Berlin, Germany; Website (private address)
Catalogs:
References: Published in Meteoritical Bulletin, no. 97, MAPS 45, 449-493 (2010)
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)
André Knöfel Photo added 19 Apr 2022
Auricular Photo added 19 Apr 2022
Photo added 19 Apr 2022
MeteoriteCollector.org - FCOM - Russ Finney Photo added 19 Apr 2022
Photo added 19 Apr 2022
Geography:

Morocco
Coordinates:Unknown.

Statistics:
     This is 1 of 1889 approved meteorites from Morocco (plus 24 unapproved names) (plus 1 impact crater)

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