Lunar Meteorite: Northwest Africa 8222 and pairs

from The Meteoritical Bulletin, No. 103

Northwest Africa 8222 (NWA 8222)

(Northwest Africa)
Purchased: 2013 Dec
Mass: 208.6 g (1 piece)

Classification: Lunar meteorite (feldspathic breccia)

History: The stone was purportedly found near Bir Anzarane, and was purchased in Temara, Morocco, by Adam Aaronson in December 2013.

Petrography: (A. Irving and S. Kuehner, UWS) Breccia consisting of separated, angular mineral clasts in a finer-grained, vesicular matrix. Minerals are olivine, anorthite, exsolved pigeonite, augite, chromite, ilmenite, troilite and minor pentlandite.

Geochemistry: Olivine (Fa_42.5; Fa_80.6; FeO/MnO = 106-134), augite (Fs_18.4Wo_40.6; FeO/MnO = 54), pigeonite consists of host orthopyroxene (Fs_50.1-50.9Wo_2.5-5.1; FeO/MnO = 58-64) with exsolution lamellae of augite (Fs_38.6Wo_41.2; FeO/MnO = 67).

Bulk composition: (R. Korotev, WUSL) INAA of subsamples gave the following mean abundances (in wt.%) FeO 3.7, Na₂O 0.37; (in ppm) Sc 7.0, Ni 90, La 1.4, Sm 0.62, Eu 0.82, Yb 0.54, Lu 0.076, Hf 0.43, Th 0.20.

Classification: Lunar (feldspathic fragmental breccia).

Specimens: A 20.1 g specimen with one polished surface is at UWB. The main mass is held by Aaronson.

from The Meteoritical Bulletin, No. 105

Northwest Africa 10823 (NWA 10823)

(Northwestern Africa)
Purchase: 2016
Mass: 202 g (2 pieces)

Lunar meteorite (feldspathic breccia)

History: Reportedly found in Western Sahara. Purchased by Steve Arnold from a Moroccan meteorite dealer in 2016.

Physical characteristics: Two identical appearing stones, weathered exterior with no fusion crust. Saw cuts reveal a polymict, feldspathic breccia with numerous white feldspar clasts, many in the range 1-5 mm, set in a dark gray matrix. There are also scattered cm-sized feldspathic clasts present. Some dark-colored domains have only sparse, fine grained, feldspathic clasts.

Petrography: (C. Agee, UNM) This meteorite is a mixture of domains with fine-grained groundmasses of pyroxene+olivine+plagioclase+opaques. Large fragmental plagioclase grains were observed throughout, shock melt veins are also present.

Geochemistry: (C. Agee and M.Spilde, UNM) olivine Fa_47.7±9.5, Fe/Mn=95±7, n=11; pigeonite Fs_41.9±9.8Wo_4.9±3.3, Fe/Mn=61±8, n=12; augite Fs_24.9±14.2Wo_37.5±6.8, Fe/Mn=61±13, n=10; plagioclase An_95.8±0.6Ab_4.0±0.6Or_0.2±0.1, n=7.

Classification: Lunar (feldspathic breccia).

Specimens: 20.02 g including a probe mount on deposit at UNM, Steve Arnold holds the main mass.

from The Meteoritical Bulletin, No. 106

Northwest Africa 11212 (NWA 11212)

(Northwest Africa)
Purchased: 2016 Nov
Mass: 197.5 g (several pieces)

Classification: Lunar meteorite (feldspathic breccia)

History: Purportedly found buried in soil in the strewnfield near Gataa Sfar and purchased by Fabien Kuntz in November 2016 from a dealer in Zagora, Morocco.

Physical characteristics: A group of small stones (total 197.5 g) lacking fusion crust. Fresh interiors exhibit white to beige clasts in a dark gray matrix.

Petrography: (A. Irving and S. Kuehner, UWS) Breccia composed of angular mineral grains of anorthite, olivine, pigeonite, ferropigeonite, subcalcic augite, augite, Ti-chromite and ilmenite in a finer grained, partly vesicular matrix containing kamacite, troilite, pentlandite, Mg-ilmenite and minor barite. Small bubbles are concentrated in groups within the matrix.

Geochemistry: Olivine (Fa_28.7-36.1, FeO/MnO = 102-116, N = 3), orthopyroxene (Fs_53.4Wo_1.7, FeO/MnO = 78), pigeonite (Fs_20.6Wo_7.8, FeO/MnO = 67), ferropigeonite (Fs_56.3Wo_21.1, FeO/MnO = 66), subcalcic augite (Fs_29.4Wo_26.4, FeO/MnO = 71), augite (Fs_9.9Wo_37.0, FeO/MnO = 68), plagioclase (An_94.2-96.7Or_0.3, N = 2).

Classification: Lunar (feldspathic breccia). Likely paired with Rabt Sbayta 002 and Rabt Sbayta 004.

Specimens: 20.28 g including one polished end cut at PSF; remainder with Kuntz.

from The Meteoritical Bulletin, No. 106

Northwest Africa 11237 (NWA 11237)

(Northwestern Africa)
Purchased: 2017 January
Mass: 583 g (1 piece)

Lunar Meteorite (feldspathic breccia)

History: Purchased by Adam Aaronson in January 2017 from a Moroccan dealer at the Tucson Gem and Mineral Show.

Physical characteristics: A single stone (583 g) lacking fusion crust. The fresh interior exhibits white to beige clasts in a medium-gray matrix.

Petrography: (A. Irving and S. Kuehner, UWS) Breccia composed of angular mineral grains of anorthite, olivine, pigeonite, exsolved pigeonite, augite, ilmenite, Ti-chromite and troilite, plus sparse glass fragments, set in a finer-grained matrix containing small vesicles and minor barite.

Geochemistry: Olivine (Fa_30.5-36.8, FeO/MnO = 99-106, N = 3), pigeonite (Fs_20.8-33.2Wo_6.2-8.4, FeO/MnO = 64-69, N = 2), orthopyroxene host (Fs_52.7Wo_1.6, FeO/MnO = 71), augite exsolution lamella (Fs_21.3Wo_43.0, FeO/MnO = 66), augite (Fs_19.5Wo_42.6, FeO/MnO = 67), anorthite (An_96.5-97.6Or_0.2-0.3, N = 2).

Classification: Lunar (feldspathic breccia)

Specimens: 20.3 g including one polished endcut at UWB; remainder with Aaronson.

from The Meteoritical Bulletin, No. 106

Rabt Sbayta 002

Rio de Oro, Western Sahara
Find: 2016 August
Mass: 6371.9 g (1 piece)

Classification: Lunar meteorite (feldspathic breccia)

History: Found by Mbarek Laghfiri and Mohamed Chikh Boy near Gataa Sfar in August 2016 and shortly thereafter. Purchased by Darryl Pitt from a Morrocan dealer in Agadir.

Physical characteristics: A single large stone (6371.9 g) lacking fusion crust but with a thin desert patina on exterior surfaces. The fresh interior exhibits pale gray to whitish clasts set in a dark gray, fine grained matrix.

Petrography: (A. Irving and S. Kuehner, UWS) Breccia composed of angular minerals clasts of anorthite, orthopyroxene, olivine, pigeonite, exsolved pigeonite, ilmenite, chromite, fayalite and Ti-chromite in a fine grained, partly vesicular matrix of the same minerals plus troilite and minor barite. Rare quench-textured lithic clasts are present.

Geochemistry: Olivine (Fa_23.4, FeO/MnO = 64; Fa_43.9, FeO/MnO = 100), orthopyroxene (Fs_58.6-60.4Wo_2.4-1.9, FeO/MnO = 57-72, N = 2), pigeonite (Fs_44.6Wo_7.9, FeO/MnO = 54; Fs_27.8Wo_21.3, FeO/MnO = 47), augite host in exsolved pigeonite (Fs_20.9Wo_38.4, FeO/MnO = 54), fayalite (Fa_78.1, FeO/MnO = 81), plagioclase (An_96.5-97.2Or_0.2, N = 2). Bulk composition (R. Korotev, WUSL) INAA of subsamples gave the following mean abundances (in wt.%) FeO 3.5, Na₂O 0.37; (in ppm) Sc 7.2, Ni 90, La 1.1, Sm 0.57, Eu 0.82, Yb 0.50, Lu 0.07, Hf 0.35, Th 0.14. Magnetic susceptibility log χ (× 10^-9 m³/kg) = 2.49.

Classification: Lunar (feldspathic breccia).

Specimens: 22.9 g in the form of a single polished slice at UWB; remainder with DPitt.

from The Meteoritical Bulletin, No. 106

Rabt Sbayta 004

Rio de Oro, Western Sahara
Find: 2016 October
Mass: 15,464 g (1 piece)

Classification: Lunar meteorite (feldspathic breccia)

History: Found by Mbarek Laghfiri and Mohamed Chikh Boy near Gataa Sfar in August 2016 and shortly thereafter. Purchased by Darryl Pitt from a Morrocan dealer in Agadir.

Physical characteristics: Found in October 2016 by Oubnaamar Salem in the lunar meteorite strewnfield near Gataa Sfar, and subsequently purchased by Darryl Pitt in December 2016 from a Moroccan dealer.

Petrography: (A. Irving and S. Kuehner, UWS) Breccia consisting of angular mineral grains of anorthite, orthopyroxene, pigeonite (some exsolved), augite, olivine, ilmenite, Cr-rich chromite, Ti-chromite, silica polymorph, fayalite, kamacite and troilite in a finer grained matrix of the same minerals. Portions of the matrix are vesicular and minor calcite is present.

Geochemistry: Olivine (Fa_38.5-84.1, FeO/MnO = 70-86, N = 5), low-Ca pyroxene (Fs_32.7-38.9Wo_2.2-5.3, FeO/MnO = 58-73, N = 4), augite (Fs_8.5-20.3Wo_45.7-40.7, FeO/MnO = 70-71, N = 3), plagioclase (An_94.6-97.3Or_0.4-0.22, N = 3).

Classification: Lunar (feldspathic breccia). Likely paired with NWA 8222 and Rabt Sbayta 002 found in the same area.

Specimens: 24.4 g in the form of a two polished endcuts at UWB; remainder with DPitt.

from The Meteoritical Bulletin, No. 106

Rabt Sbayta 005

Rio de Oro, Western Sahara
Find: 2016 August
Mass: 20.78 g (4 pieces)

Classification: Lunar meteorite (feldspathic breccia)

History: The four fragments were found on a deflation surface by Salem Ben Amar and Amar Zerwal in August 2016. They were purchased from Mohamed Elguirah by Jean Redelsperger in Tan Tan in September 2016.

Physical characteristics: Uncrusted, irregular, dark stones with whitish clasts. Cut surface reveals dark interior with white clasts up to 2 mm.

Petrography: (J. Gattacceca, CEREGE) Brecciated with lithic and mineral clasts (olivine, pigeonite, plagioclase) in a very fine grained plagioclase matrix. Numerous vesicles with diameter 10-20 μm. are present in the matrix. Accessory minerals include chromite, ilmenite. Rare kamacite.

Geochemistry: Olivine Fa_33.9±3.3, range Fa_31.4-41.2, FeO/MnO = 85.8±9.7 (range 67-98), N=6. Pigeonite Fs_40.5±0.8Wo_10.2±3.1, FeO/MnO=54.0±6.5 (N=5). Plagioclase An_96.5±0.6Ab_3.4±0.6Or_0.1±0.0 (N=4). Chromite Cr#=Cr/(Cr+Al)=0.64-0.67 (N=2). Magnetic susceptibility log χ (× 10-9 m³/kg) = 2.58.

Classification: Lunar (feldspathic breccia). Likely paired with Rabt Sbayta 002 and Rabt Sbayta 004 found in the same area.

Specimens: 4.44 g and polished section at CEREGE. Main mass with Jean Redelsperger.

from The Meteoritical Bulletin, No. 106

Rabt Sbayta 006

Rio de Oro, Western Sahara
Find: 2016
Mass: 4810 g (2 pieces)

Classification: Lunar meteorite (feldspathic breccia)

History: Found in the lunar meteorite strewnfield near Gataa Sfar in 2016. Purchased by Terry Boudreaux from a Moroccan meteorite dealer in 2017.

Physical characteristics: Four identical appearing uncrusted pieces found together. A saw cut reveals a fragmental breccia with numerous white feldspathic clasts set in a dark-gray ground mass.

Petrography: (C. Agee, UNM) This meteorite consists of primarily feldspathic clasts and shock melt with lesser amounts of fragmental pyroxene and olivine.

Geochemistry: (C. Agee and B. Ha, UNM) olivine Fa45.8±5.7, Fe/Mn=97±8, n=7; pigeonite Fs_42.1±7.5Wo_6.9±5.2, Fe/Mn=59±6, n=8; high Ca pyroxene Fs_28.3±11.7Wo_33.7±6.8, Fe/Mn=56±13, n=5; plagioclase An_96.1±0.8Ab_3.7±0.8Or_0.2±1.0, n=6; Shock melt (20 μm defocused electron beam, proxy for bulk meteorite composition): SiO₂=43.9±0.3, TiO₂=0.13±0.06, Al₂O₃=33.2±1.9, Cr₂O₃=0.05±0.04, MgO=2.1±1.2, FeO=2.8±1.4, MnO=0.05±0.02, CaO=18.2±0.9, NiO=0.03±0.04, Na₂O=0.39±0.03, K₂O=0.03±0.01 (all wt%), n=12.

Classification: Lunar feldspathic breccia

Specimens: 21.74 g including a probe mount on deposit at UNM, Boudreaux holds the main mass.

Randy Says…

Compositionally, the Northwest Africa 8222 clan is a typical feldspathic lunar meteorite. I have not analyzed Rabt Sbayta 005 and 006; I assume that they are paired with the others on the basis of the descriptions and find locations. Together, these stones comprise one of the largest lunar meteorites, 28 kg.

More Information

Meteoritical Bulletin Database

NWA 8222 | 10823 | 11212 | 11237 |
Rabt Sbayta 002 | 004 | 005 | 006

References

Korotev R. L. and Irving A. J. (2015) Keeping up with the lunar meteorites – 2015. 46th Lunar and Planetary Science Conference, abstract no. 1942.

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