This is 1 of 5 approved meteorites classified as Lunar (melt breccia). Northwest Africa 13757 (NWA 13757) 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.