Lunar Meteorite: Northwest Africa 10608 & Aridal 017 (pairs?)

northwestern Africa

Aridal 017. Photo credit: David Gregory

Two views of Northwest Africa 10608. Photo credit: Carl Agee

Two views a lab sample of Aridal 017. Photo credit: Randy Korotev

from The Meteoritical Bulletin, No. 105

Northwest Africa 10608 (NWA 10608)

(Northwest Africa)
Purchased: 2016
Mass: 2014 g (1 piece)

Lunar meteorite (feldspathic breccia)

History: Purchased by Jay Piatek in Morocco, 2016.

Physical characteristics: Single stone, weathered exterior without fusion crust; broken surface reveals numerous white feldspathic clasts set in a dark-gray groundmass.

Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows a fragmental breccia with numerous olivine, pigeonite, and augite grains set in a dominant feldspathic matrix. Lithic and melt clasts also observed. Pigeonite, augite, and olivine show igneous crystallization, iron-enrichment trends.

Geochemistry: (C. Agee and S. Spilde, UNM) Olivine Fa22.2±15.5, Fe/Mn=91±7, n=15; pigeonite Fs32.3±10.6Wo5.7±3.4, Fe/Mn=58±4, n=7; augite Fs21.2±13.4Wo39.1±5.3, Fe/Mn=50±14, n=3; plagioclase An95.3±2.4, n=2.

Classification: Lunar feldspathic breccia.

Specimens: 20.8 g including a probe mount on deposit at UNM, Jay Piatek holds the main mass.

from The Meteoritical Bulletin, No. 107

Aridal 017

Rio de Oro, Western Sahara
Purchased: 2016 September
Mass: 590 g (1 piece)

Lunar meteorite (feldspathic breccia)

History: Found in Morocco in sandy soil, several meters from the find site for Northwest Africa 10608 (which was found earlier by desert truffle hunters). The stone was purchased by Dr. David Gregory in September 2016 from a Moroccan dealer at the Denver Show.

Physical characteristics: A single grayish stone (590 g) lacking fusion crust but with a glossy external patina. The fresh interior consists of small whitish clasts in a dark-gray matrix.

Petrography: (A. Irving and S. Kuehner, UWS) Breccia composed of angular mineral clasts of anorthite, olivine, orthopyroxene, pigeonite, ferropigeonite, augite, silica polymorph, TI-chromite and ilmenite (with rare inclusions of baddeleyite) in a fine grained matrix of the same minerals plus minor kamacite, troilite and K-bearing glass.

Geochemistry: Olivine (Fa10.1-27.0, FeO/MnO = 74-106, N = 3), orthopyroxene (Fs20.9Wo4.5, FeO/MnO = 51), pigeonite (Fs21.7Wo­, FeO/MnO = 54), ferropigeonite (Fs63.1Wo18.5, FeO/MnO = 72), augite (Fs17.3Wo40.5, FeO/MnO = 46), anorthite (An95.2-95.4Or0.5, N = 2).

Classification: Lunar (feldspathic regolith breccia). This stone was found at the same place as Northwest Africa 10608 and probably is paired with it.

Specimens: 10.1 g including one polished endcut at UWB; 10.1 g at ROM; main mass with Gregory.

Randy Says…

I have not analyzed NWA 10608 but assume these two stones are paired because of the proximity statement above, the same year of purchase, and the similarity in appearance. Compositionally, Aridal 017 is a (perhaps troctolitic?) feldspathic lunar meteorite.

More Information

Meteoritical Bulletin Database

NWA 10608 | Aridal 017

References

Korotev R. L. and Irving A. J. (2021) Lunar meteorites from northern Africa. Meteoritics & Planetary Science, 206–240. 

Lunar Meteorites | List of Lunar meteorites