The mineral assemblage of symplectites in lunar meteorite Asuka-881757.

Asuka-881757 with a gabbro-like texture is from lunar mare. It is different from other known lunar mare basaltic meteorites. It is coarse-grained basalt with symplectite texture in mesostasis. It is composed mainly of pyroxene and maskelynite (An_<90>∿An_<96>). Most ilmenites, troitites and some Fe-Ni metals are surrounded by symplectite. One of the symplectites consists of very fine-grained Fe-rich olivine (Fa_<93>) and silica phase in pyroxene host around troilite. However, the troilite and primary pyroxene did not react to form the symplectite. The coexisting fayalite, hedenbergitic pyroxene and silica phase suggest that they crystallized from the primary melt at a pressure lower than 1.15GPa, indicating formation near the lunar surface.