Achondrite, ungrouped
Orthopyroxenite
click on photos for a magnified view
Purchased January 2022
no coordinates recorded
A relatively fresh mass weighing 1,326 g was purchased by Craig Zlimen from an Algerian meteorite dealer. After a small portion was sold to collectors, the remainder was acquired by L. Labenne. A type specimen was sent for analysis and classification to the University of Washington in Seattle (A. Irving), Washington University in St. Louis (P. Carpenter), and Brown University in Providence (D. Ibarra, oxygen isotopes), and NWA 15130 was classified as an ungrouped achondrite, specifically an ultramafic orthopyroxenite.
Northwest Africa 15130 is composed primarily of magnesian orthopyroxene (92.7 vol%, Fs15.5–17.5) together with a small component of FeNi-metal (5.8 vol%), along with minor plagioclase (1.5 vol%, plus intergrown silica polymorph), farringtonite, schreibersite, and troilite. The oxygen isotopic composition plots within the field of brachinites (see diagram below).
Meteoritical Bulletin Oxygen Isotope Plots—The Meteoritical Society
The specimen of NWA 15130 shown above is a 5.93 g partial slice. The photos show the slice in both reflected light and backlit showing translucent orthopyroxene crystals. The photo below shows a portion of NWA 15130 as an in situ xenolith in a slice of the El Eglab 001 mesosiderite. All photos are shown courtesy of Craig Zlimen.
