What is a serpentinite in geology ?
Serpentinite : definition
Serpentinites consist almost entirely of minerals from the serpentine group : dominant antigorite, dark green, traversed by greenish veinlets of chrysotile, accompanied by a little iron oxide, generally in the form of spinels. The olivines and sometimes the pyroxenes of the original rock frequently appear as residues within an antigorite framework : the serpentinite then takes on a porphyritic appearance. The rock, green in color, with light green and dark green areas, reminiscent of snake skin (hence its name), has a characteristic smooth feel.