This Martian meteorite is a coarse grained gabbroic shergottite, formed by relatively slow but steady cooling of a body of magma beneath the surface of Mars.  This image (captured in cross-polarized light) shows that it is contains large prismatic grains of pyroxene (exhibiting variable beige, blue and yellow colors, caused by variations in chemical composition as the grains grew from the parent magma).  In addition there are curvilinear grains (white in this image) of a glassy material called maskelynite (formed by shock transformation of original crystalline plagioclase during ejection from Mars) and small black (opaque) grains of oxide minerals.  Unlike Northwest Africa 10961, this shergottite specimen does not contain olivine.  Sepia brown areas with in part swirly textures are pockets of glass formed by localized shock melting of the bulk rock, and it is such portions of other shergottite specimens that tiny amounts of trapped Martian atmospheric gases have been detected.