Lunar Meteorite: Northwest Africa 16484

A 12.7-g slice of Northwest Africa 16484. Photo credit: Matthew Stream
Clasts in NWA 16484. Photo credit: Matthew Stream
Fragments from the 2-4-mm grain-size-fraction of Apollo 11 soil sample 10085. The fragment in the center has a blue-green tint as do some of the clasts in NWA 16484, thus the color in the meteorites is probably not a terrestrial weathering effect. Apollo samples, especially feldspathic samples, are remarkably uncolorful. Speculation: Compared to mineralogically equivalent terrestrial rocks, lunar rocks are rich in chromium and chromium is a chromophore. For example, green wine bottles are green because they contain several hundred parts-per-million chromium as well as 0.2-0.5% iron. Photo credit: Randy Korotev

from The Meteoritical Bulletin, No. 113

Northwest Africa 16484 (NWA 16484)

(Northwestern Africa)
Purchased: 2023
Mass: 292 g (2 pieces)

Lunar meteorite (fragmental breccia)

History: Purchased in 2023 by Craig Zlimen from a meteorite dealer in Morocco.

Physical Characteristics: Two pieces with fusion crust.

Petrography: (D. Sheikh, Cascadia) Sample is a polymict breccia comprised of mm-sized, angular to sub-rounded lithic and mineral clasts set within a fine-grained fragmental matrix. Clast lithologies identified include: troctolites, gabbros, anorthosites, basalts, impact melt clasts; an Mg-suite troctolite clast contains a noticeable symplectite displaying a vermicular texture comprised of Cr-spinel, augite, and orthopyroxene. Accessory phases identified within the host rock include troilite, Ca-phosphates (apatite/merrillite), ilmenite, and Fe-Ni metal.

Geochemistry: Olivine (Fa30.4±15.0, range Fa19.6-66.5, Fe/Mn=84±13, n=12), Low-Ca Pyroxene (Fs27.7±10.1Wo3.1±0.3, range Fs16.5-44.8Wo2.3-3.6, Fe/Mn=56±9, n=18), Pigeonite (Fs44.4±11.5Wo15.0±6.7, range Fs27.4-60.8Wo5.8-24.4, Fe/Mn=57±8, n=17), Augite (Fs33.8±22.0Wo36.2±6.4, range Fs7.4-60.4Wo26.9-45.8, Fe/Mn=54±14, n=13), Calcic Plagioclase (An95.8±2.1, range An90.3-97.8, n=22).

Classification: Lunar (fragmental breccia) due to polymict nature of the sample.

Specimens: 20.2 g at Cascadia, main mass with Craig Zlimen.

Randy Says…

I have not studied Northwest Africa 16484.

More Information

Meteoritical Bulletin Database

NWA 16484

Lunar Meteorites
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