Mylonitic Peridotite

Or at least is once was, since except for the chromite grains (black-redblack grains, the largest about 0.5 cm across), the other phases are serpentinized, and the rock is crossed by green veins of serpentine.

A strong foliation is apparent on the scanned surface, this part of a mylonitic deformation that affected the rock long before the serpentinization took place. Peridotites of this appearance were deformed at temperatures of around 1000 C.