Northwest Africa 13989 (NWA 13989)

(Northwest Africa)

Purchased: 2021

Classification: Lunar meteorite (frag. breccia)

History: Purchased from an Algerian meteorite dealer in 2021.

Physical characteristics: This meteorite is a single stone with a hemispherical shape and a dark colored, shiny, sandblasted surface with numerous light-colored clasts visible. A sawm surface reveals a feldspathic breccia host. Contained within the host breccia are distinctive light brown/orange clasts scattered throughout. Some of the brown/orange clasts are up to 1 cm in length.

Petrography: (C. Agee, UNM) Electron microprobe analysis of a polished mount shows this meteorite to be a lunar polymict breccia with a feldspathic breccia host rock consisting of fragments of ferroan olivine and pyroxene, and bytownite plagioclase (Lithology 1) and within it are crystalline domains that appear to be monomineralic aluminous ferro-augite (Lithology 2). Lithology 1 has accessory silica, merrillite, zircon, Fe-sulfide, ilmenite, and two spinels. Lithology 2 has small, sparse inclusions of ilmenite, olivine, pyroxene, and anorthitic plagioclase.

Geochemistry: (A. Ross, UNM) Lithology 1: olivine Fa_60.8±16.5, Fe/Mn=98±9, n=12; clinopyroxene Fs_29.7±9.6Wo_23.3±8.4, Fe/Mn=72±9, n=15; plagioclase An_78.2±9.0, n=7. Lithology 2: aluminous ferro-augite Fs_43.6±0.1Wo_28.1±0.2, Fe/Mn=82±8, Al₂O₃=10.4±0.1 (wt%) n=4.

Classification: Polymict fragmental lunar breccia

Specimens: 20 g on deposit at UNM, Craig Zlimen, Tom Thiegs and Brett Cohen hold the main mass.