Lunar Meteorite: Northwest Africa 13676, 13757, & 13908

Presumed paired stones

Three views of Northwest Africa 13676 (698 g). Photo credits: Ziyao Wang

from The Meteoritical Bulletin, No. 110

Northwest Africa 13676 (NWA 13676)

Algeria
Purchased: 2020 September
Mass: 698 g (1 piece)

Classification:  Lunar meteorite (feldspathic breccia)

History: Purchased by Didi Baideri in September 2020 from an Algerian dealer and subsequently sold to Ziyao Wang in December 2020.

Physical characteristics: A single dark, very fine grained stone (698 g) coated by a shiny patina.

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Fine grained breccia composed of mineral clasts of anorthite, olivine, pigeonite and augite, plus feldspathic lithic clasts (including quench-textured melt clasts), set within a very fine grained, partly vesicular matrix containing kamacitic metal (with variable Fe:Ni) and chromite (with variable Ti content).

Geochemistry: Olivine (Fa26.6-42.8, FeO/MnO = 87-105, N = 6), pigeonite (Fs23.4-35.1Wo6.6-10.2, FeO/MnO = 52-64, N = 5; Fs39.7-47.2Wo14.9-16.7,FeO/MnO = 54-58, N = 2), augite (Fs20.8Wo37.4, FeO/MnO = 56), anorthite (An94.8-95.5Or0.3-0.5, N = 3).

Classification: Lunar (feldspathic breccia).

Specimens: 221.8 g including one polished endcut at UWB; remainder with Mr. Z. Wang.

from The Meteoritical Bulletin, No. 110

Northwest Africa 13757 (NWA 13757)

Algeria
Purchased: 2020 December
Mass: 16974 g (many pieces)

Classification:  Lunar meteorite (melt breccia)

History: Numerous stones (purportedly found at the same unspecified site in Algeria which produced NWA 13676) were purchased by Darryl Pitt in December 2020 from a dealer in Zagora, Morocco.

Physical characteristics: All of the stones (total weight 16974 g) are dark gray and relatively fine grained with an exterior shiny patina.

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Breccia composed of mineral clasts of anorthite, olivine, low-Ca pyroxene, pigeonite and augite plus mafic lithic clasts in a very fine grained matrix containing partially altered kamacite, both high-Ti and low-Ti chromite, and minor secondary barite and celestite. These specimens are richer in mafic components by comparison with typical feldspathic lunar breccias. Mafic lithic clasts include microgabbro, subophitic olivine-bearing mare basalt and quench-textured basalt lithologies. The matrix exhibits some fluidal alignment of elongate mineral clasts and is sparsely microvesicular.

Geochemistry: Olivine (Fa26.2-41.1, FeO/MnO = 81-92, N = 5), low-Ca pyroxene (Fs27.8Wo4.4, FeO/MnO = 60), pigeonite (Fs23.9-35.9Wo13.5-18.6, FeO/MnO = 43-52, N = 3), subcalcic augite (Fs43.6Wo32.4, FeO/MnO = 51), augite (Fs11.0Wo38.4, FeO/MnO = 41), anorthite (An93.8-96.6Or0.4-0.1, N = 3).

Classification: Lunar (melt breccia). This material has textural, petrologic and mineral chemical features consistent with being paired to the stone classified as NWA 13676, and was procured from the same Algerian source.

Specimens: 20.85 g in the form of a polished endcut at UWB; remainder with DPitt.

from The Meteoritical Bulletin, No. 110

Northwest Africa 13908 (NWA 13908)

(Northwest Africa)
Purchased: 2020 December
Mass: 1680 g (1 piece)

Classification:  Lunar meteorite (melt breccia)

History: Purchased in Agadir, Morocco by Aziz Habibi in December 2020.

Physical characteristics: A single dark gray, relatively fine grained stone (1680 g) with an exterior shiny patina.

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Breccia composed of mineral clasts of anorthite, olivine, pigeonite, exsolved pigeonite and augite plus mafic lithic clasts in a very fine grained matrix containing metal (with variable Fe:Ni intermediate between values for kamacite and taenite), chromite and ilmenite. Mafic lithic clasts include microgabbro and quench-textured basalt lithologies. The matrix exhibits some fluidal alignment of elongate mineral clasts and is sparsely microvesicular.

Geochemistry: Olivine (Fa24.0-37.5, FeO/MnO = 77-92, N = 5), pigeonite (Fs25.3-41.1Wo8.0-16.6, FeO/MnO = 40-59, N = 4), subcalcic augite (Fs21.1-28.6Wo27.1-32.6, FeO/MnO = 51-53, N = 2), augite (Fs23.3Wo40.9, FeO/MnO = 52), low-Ca pyroxene host (Fs46.0Wo3.2, FeO/MnO = 67), augite exsolution lamella (Fs19.9Wo42.8, FeO/MnO = 58), anorthite (An96.5-97.6Or0.2-0.0, N = 3).

Classification: Lunar (melt breccia). This material has textural, petrologic and mineral chemical features consistent with being paired to the stones classified as NWA 13676 and NWA 13757.

Specimens: 23.0 g including a polished mount at UWB; remainder with Mr. A. Habibi.

Randy Says…

I have not studied these 3 meteorites. I assume that they are paired on the basis of the descriptions.

More Information

Meteoritical Bulletin Database

NWA 13676 | 13757 | 13908