What is a serpentinite in geology ?
Serpentinite : definition
A serpentinite is a green rock deriving by meteoric or hydrothermal weathering, or by metamorphism, from ultrabasic magmatic rocks, mainly peridotites, and occasionally from basic rocks.
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.
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.