schist
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/shist/, n.any of a class of crystalline metamorphic rocks whose constituent mineral grains have a more or less parallel or foliated arrangement.[1775-85; < NL schistus, L (lapis) schistos < Gk schistós divided, curdled, divisible, deriv. of schízein to split, with -tos adj. suffix]
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Crystalline metamorphic rock that has a highly developed tendency to split into layers.Most schists are composed largely of platy minerals such as muscovite, chlorite, talc, biotite, and graphite. The green colour of many schists and their formation under a certain range of temperature and pressure conditions have led to distinction of the greenschist facies in the mineral facies classification of metamorphic rocks. Schists are usually classified on the basis of their mineralogy, with varietal names that indicate the characteristic mineral present.* * *
▪ mineralmegascopically crystalline rock that has a highly developed schistosity, or tendency to split into layers. Banding (foliation) is typically poorly developed or absent. Most schists are composed largely of platy minerals such as muscovite, chlorite, talc, sericite, biotite, and graphite; feldspar and quartz are much less abundant in schist than in gneiss. The green colour of many schists and their formation under a certain range of temperature and pressure has led to a distinction of the greenschist facies in the mineral facies classification of metamorphic rocks. The parallel orientation of the platy minerals and well-developed folding of many schists indicate formation under stresses that are not the same in all directions. The mineralogy and high water content of the minerals indicate that they were formed under conditions of relatively low temperature and pressure.Schists are usually classified on the basis of their mineralogy, with varietal names that indicate the characteristic mineral present. Talc schist contains abundant talc; it has a greasy feel, a well-developed schistosity, and a grayish-green colour. Mica schist often contains muscovite mica rather than biotite, although both minerals are common. It represents a somewhat higher grade of metamorphism than talc schist and is more coarse-grained; individual flakes of mica can be seen.* * *
Universalium. 2010.
Look at other dictionaries:
Schist — The schists constitute a group of medium grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn out grains to such an… … Wikipedia
Schist — (sh[i^]st), n. [Gr. ? divided, divisible, fr. ? to divide: cf. F. schiste. See {Schism}.] (Geol.) Any crystalline rock having a foliated structure (see {Foliation}) and hence admitting of ready division into slabs or slates. The common kinds are… … The Collaborative International Dictionary of English
schist — schist, schisturi, s.n. (înv.) 1. stâncă în straturi subţiri de ardezie. 2. ulei mineral extras din şişturile (şist) bituminoase, folosit la iluminat. Trimis de blaurb, 13.09.2007. Sursa: DAR … Dicționar Român
schist — [ʃıst] n [U] [Date: 1700 1800; : French; Origin: schiste, from Latin schistos (lapis) stone that can be split , from Greek, from schizein; SCHISM] a type of rock that naturally breaks apart into thin flat pieces … Dictionary of contemporary English
schist — (n.) 1795 (earlier schistus, c.1600), from Fr. schiste, from L. schistos lapis stone that splits easily (Pliny), from Gk. skhistos divided, separated, from skhizein to split (see SHED (Cf. shed) (v.)). The rock splits easily in layers. Liddell… … Etymology dictionary
schist — a term in geology for a type of layered rock, is pronounced shist … Modern English usage
schist — [shist] n. [Fr schiste < L schistos (lapis), split (stone) < Gr schistos, easily cleft < schizein, to cleave: see SCHIZO ] any of a group of metamorphic rocks containing parallel layers of flaky minerals, as mica or talc, and splitting… … English World dictionary
schist — an·a·schist·ic; schist; schist·oid; schist·ose; schist·ous; … English syllables
schist — n. foliated metamorphic crystalline rock. ♦ schistaceous, a. slate coloured. ♦ schistic, ♦ schistose, a. ♦ schistoid, a. like schist. ♦ schistosis, n. fibrosis of lungs from inhaling slate dust … Dictionary of difficult words
schist — skalūnas statusas T sritis chemija apibrėžtis Į plonas plokšteles skylanti nuosėdinė metamorfinė uoliena. atitikmenys: angl. schist; shale rus. сланец … Chemijos terminų aiškinamasis žodynas
