Consists primarily of epidote, actinolite, chlorite, and plagioclase. A hydration and metamorphic transformation of ultramafic rock from the Earth's mantle is called as serpentinization, a group of minerals is formed by serpentinization compose rock 'serpentinite'.. Minerals in this group are formed by serpentinization, a hydration and metamorphic transformation of ultramafic rock from the Earth's mantle. It consists of serpentine phyllosilicate minerals. Template:Use dmy dates Serpentinite is a rock composed of one or more serpentine group minerals. Serpentinite is a rock composed of one or more serpentine group minerals, the name originating from the similarity of the texture of the rock to that of the skin of a snake. Serpentinization of peridotite involves internal buffering of the pore fluid, reduction of oxygen fugacity, and partial oxidation of Fe 2+ to Fe 3+ . This rock is created with slightly more water than serpentinite, making soapstone softer. 8.9 Sheared serpentinite with pencil for scale, Marin County, California. Serpentinite Serpentinite is a metamorphic rock that is mostly composed of serpentine group minerals. Often, as here, serpentinite contains bands of the thin, fibrous, asbestos mineral chrysotile. Serpentine group minerals antigorite, lizardite, and chrysotile are produced by the hydrous alteration of ultramafic rocks. Soapstone, also known as steatite, is a rock that is also formed from peridotite. Serpentinite forms from the metamorphic alteration of ultramafic silicate rocks, particularly peridotite and pyroxenite, where serpentine minerals replace igneous minerals of olivine and pyroxene. Serpentinite is a metamorphic rock consisting almost entirely of "serpentine group minerals." The alteration is particularly important at the sea floor at tectonic plate boundaries. This sample measures 85 millimetres across. Serpentinite is a fibrous ± vein-type, nonfoliated, green-black metamorphic rock composed predominantly of serpentine minerals (see serpentine subgroup). Serpentinite is a metamorphic rock, formed when igneous rocks are oxidised and hydrolysed by water. Often found in low-grade metamorphic areas, serpentinite is composed of hydrated silicate minerals, particularly phyllosilicates. Rocks that form at high temperatures generally do not have the same problems. Serpentinite is a metamorphosed ultramafic rock. Blackstone Group - greenstone, amphibolite, serpentinite - Dark-green, massive to foliated metamorphosed gabbroic and basaltic rock interlayered with epiclastic rock; local pillow-structures preserved. Soapstone contains talc and chlorite, which can make the rock feel slippery. Serpentinite metamorphic rock. These rocks are composed of many distinct minerals. The first is serpentinite. A rock composed of one or more serpentine group minerals, e.g., antigorite, chrysotile and lizardite, formed by serpentinization (hydration and metamorphic transformation) of rock consisting almost wholly of ferromagnesian silicate minerals, such as olivine and pyroxene (usually ultramafic igneous rocks). However, there are many kinds of metamorphic rocks, and some of them are more chemically reactive than others. Serpentinite forms at the expense of olivine- and pyroxene-bearing rocks. Serpentine forms from the alteration of ultramafic igneous rocks under low grade metamorphic conditions in the presence of lots of water so any circumstances that provide these conditions will result in serpentinite. It is a metamorphic magnesium rich rock because it is composed of the mineral talc. Serpentinite is a dense, dark green rock that can contain asbestos. Rock-forming serpentine minerals form flat, cylindrical, and corrugated crystal microstructures, which reflect energetically efficient layering of alternate tetrahedral and octahedral sheets. When clay- and aluminum-rich rock is altered by water from geothermal systems, serpentinite is liable to form. Includes rock mapped formerly as Hunting Hill Greenstone. Aside from these conditions there is no specific tectonic association associated with serpentinite. Accessory chlorite, talc, and magnetite may be present.