Lunar Meteorite

Larkman Nunatak 06638



Larkman Nunatak 06638 

(photo credit: NASA)

Small samples of LAR 06638. Millimeter ticks for scale.

(photo credit: Randy Korotev)


Back-scattered electron image (gray-scale) and a red-green-blue elemental x-ray map of a thin section of LAR 06638. In BSE images, brightness increases with mean atomic mass. The darkest areas are rich in plagioclase (Al) and the lightest areas are rich in mafic (Fe-bearing) minerals. In the X-ray map, areas rich in Al (e.g., plagioclase) are bright red, areas rich in Mg are bright green (e.g., olivine), and areas rich in Fe (e.g., pyroxene or FeNi metal) are bright blue. Notice that there are three different layers of glass coating, not all of which may be fusion crust in that the two inner ones have differnt compositions. The scale bar applies to the BSE image.

(image credit: Ryan Zeigler)


Listed in from The Meteoritical Bulletin, No. 94, September 2008. Meteoritics & Planetary Science 43, 1551–1588 (2008)

Classification from Antarctic Meteorite Newsletter, Vol. 30, No. 2, 2007

LAR 06638

Sample No.: LAR 06638
Location: Larkman Nunatak
Field No.: 19362
Dimensions (cm): 2.5 x 2.0 x 0.75
Mass: 5.293 g

Lunar-Anorth. Breccia

Macroscopic Description: Kathleen McBride The bottom exterior surface has black fusion crust, while the top has a lighter brown crust. Polygonal fractures are present. The gray and white matrix has a sharp line where matrix becomes black with white inclusions.

Thin Section (,2) Description: Tim McCoy, Lauren LaCroix and Linda Welzenbach. The section shows a groundmass of comminuted pyroxene, olivine and plagioclase with grain sizes up to 1 mm. Clasts up to 2 mm include basalts, granulites and anorthosites. One-half of the section exhibits a darkened matrix. Olivine is Fa28-33, pyroxene ranges from Fs27-39Wo3-12 (Fe/Mn ~ 60), and plagioclase An93-98. The meteorite is lunar, probably an anorthositic regolith breccia.


Randy Says…

Compositionally, LAR 06638 is a typical feldspathic lunar meteorite.


More Information

Meteoritical Bulletin Database

LAR 06638



ANSMET Location Map



Korotev R. L. and Zeigler R. A. (2014) Chapter 6. ANSMET Meteorites from the Moon, Thirty-five Seasons of U.S. Antarctic Meteorites (1976–2010): A Pictorial Guide to the Collection (editors K. Righter, R. P. Harvey, C. M. Corrigan, and T. J. McCoy), 101–130, Special Publications 68, American Geophysical Union, Washington, D. C., 296 pages, ISBN: 978-1-118-79832-4.

Korotev R. L., Irving A. J., and Bunch T. E. (2008) Keeping up with the lunar meteorites - 2008. Lunar and Planetary Science XXXIX, abstract no. 1209.

Korotev R. L., Jolliff B. L., and Zeigler R. A. (2010) On the origin of the moon’s feldspathic highlands, pure anorthosite, and the feldspathic lunar meteorites. 41st Lunar and Planetary Science Conference, abstract no. 1440.

Zeigler R. A. and Korotev R. L. (2013) Petrography and geochemistry of feldspathic lunar meteorite Larkman Nunatak 06638. 44th Lunar and Planetary Science Conference, abstract no. 1767.



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Prepared by: Randy L. Korotev

Department of Earth and Planetary Sciences
Washington University in St. Louis

Please don’t contact me about the meteorite you think that
you’ve found until you read this and this.



Last revised: 29 May 2019