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Chlorite schist, a type of greenschist Greenschist (prasinite) at Cap Corse in Corsica, France Greenschist (epidote) from Itogon, Benguet, Philippines. Greenschists are metamorphic rocks that formed under the lowest temperatures and pressures usually produced by regional metamorphism, typically 300–450 °C (570–840 °F) and 2–10 kilobars (29,000–145,000 psi). [1]
Mineral qualifiers are important when naming a schist. For example, a quartz-feldspar-biotite schist is a schist of uncertain protolith that contains biotite mica, feldspar, and quartz in order of apparent decreasing abundance. [14] Lineated schist has a strong linear fabric in a rock which otherwise has well-developed schistosity. [10]
Some rock types containing chlorite, such as chlorite schist, have minor decorative uses or as construction stone. However, chlorite is a common mineral in clay, which has a vast number of uses. [9] Chlorite schist has been used as roofing granules, the mineral granules adhered to asphalt composition shingles due to the green color.
Although grain coarsening is a common result of metamorphism, rock that is intensely deformed may eliminate strain energy by recrystallizing as a fine-grained rock called mylonite. Certain kinds of rock, such as those rich in quartz, carbonate minerals , or olivine, are particularly prone to form mylonites, while feldspar and garnet are ...
By mass, "pure" steatite is roughly 63.37% silica, 31.88% magnesia, and 4.74% water. [2] It commonly contains minor quantities of other oxides such as CaO or Al 2 O 3 . Pyrophyllite , a mineral very similar to talc, is sometimes called soapstone in the generic sense, since its physical characteristics and industrial uses are similar, [ 3 ] and ...
It is very common in sedimentary rocks such as sandstone and shale. It is a common constituent of schist, gneiss, quartzite and other metamorphic rocks. [22] Quartz has the lowest potential for weathering in the Goldich dissolution series and consequently it is very common as a residual mineral in stream sediments and residual soils.
The other common mica mineral, biotite, is almost always much darker in color than muscovite. Paragonite can be difficult to distinguish from muscovite but is much less common, though it is likely mistaken for muscovite often enough that it may be more common that is generally appreciated. [9] Muscovite mica from Brazil is red due to manganese ...
Talc in powdered form, often combined with corn starch, is used as baby powder. This mineral is used as a thickening agent and lubricant. It is an ingredient in ceramics, paints, and roofing material. It is a main ingredient in many cosmetics. [6] It occurs as foliated to fibrous masses, and in an exceptionally rare crystal form.