Y-790447, 51-1: Eucrite

         A small broken piece similar to polymict eucrite, but more fragmented. The bottom flat face seems to be abraded. Black fusion crusts are preserved on the top portion. Finer-grained lithic clasts with white laths of plagioclases and gray pyroxenes are abundant.

         A eucritic breccia composed of nearly equigranular pyroxene crystals of dark brown rim and subrounded to short prismatic plagioclase crystals with dusty appearance, and a few opaque minerals. The boundaries between lithic clasts and mineral fragments are not easily recognized, as the pyroxene-rich matrices have dark colored sintered appearance and lack fine grained fragmental materials. In one area, dark yellowish brown pyroxene form continuous domains with a few scattered fragments of plagioclase. Some pyroxene crystals have light colored cores with brownish rims, as in the Y-790266 eucrite. In some areas, a basaltic crystalline texture is preserved, but in other areas such textures are disturbed and matrix looks like fine-grained compacted or sintered dark pyroxenes.

         A large pyroxene crystal reaches up to 1 mm in length, a light colored pyroxene fragment includes euhedral chromites. Pyroxenes with exsolution or dark striation also present. The chemical compositions of pyroxene include Mg-rich components up to Mg/(Mg+Fe)=97, but it is not clear whether they represent diogenitic components or survival of unhomogenized Mg-rich cores of zoned pyroxenes as in Y-790266. The plagioclase composition ranges from An₇₇ to An₉₅.