Minerals - 22 of 21
Minerals FAQs - 21 Found
Serpentine is a family of silicate minerals rich in magnesium and water, derived from low-temperature alteration or metamorphism of the minerals in ultramafic rocks (intrusive igneous rocks very rich in iron and magnesium and with much less silicon and aluminum than most crustal rocks, most come from the Earth's mantle). Serpentine minerals are light to dark green, commonly varied in hue, and greasy looking; the mineral feels slippery.
Rocks made up of serpentine minerals are called serpentinite.
The Origin of Serpentinite:
The origin of serpentinite is inferred to be a metamorphic alteration (called serpentinization) of mantle rock or oceanic crustal rock.
Grades of Serpentinite:
Serpentinite is considered greenschist grade, a metamorphic facies associated with low temperature, low pressure conditions relative to other grades of metamorphic rocks. Higher pressure metamorphic grades of serpentinite contain glaucophane (a pale bluish-gray to black serpentine mineral that occurs in fibrous to felted aggregate masses). Higher temperature and pressure metamorphic grades contain garnets, pyroxene- and amphibole-minerals and are grouped into a metamorphic class called 'eclogite'.