schist


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Related to schist: Mica schist, amphibolite

schist

(shĭst), metamorphic rockrock,
aggregation of solid matter composed of one or more of the minerals forming the earth's crust. The scientific study of rocks is called petrology. Rocks are commonly divided, according to their origin, into three major classes—igneous, sedimentary, and metamorphic.
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 having a foliated, or plated, structure called schistosity in which the component flaky minerals are visible to the naked eye. Schists are distinguished from the other foliated rocks, slates and gneisses, by the size of their mineral crystals; these are larger than those of slates, being visible to the naked eye, but smaller than those of gneisses, which are coarsely foliated rocks as opposed to finely foliated, or schistose, rocks. As contrasted with the folia of slates, the folia of schists are rough-surfaced and irregular. Schists split readily along their planes of schistosity, like slates along cleavage lines. Like other foliated rocks, schists owe their origin to the metamorphism of preexisting rocks. The commonest of the schists is mica schist, the essential minerals of which are quartzquartz,
one of the commonest of all rock-forming minerals and one of the most important constituents of the earth's crust. Chemically, it is silicon dioxide, SiO2.
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 and micamica
, general term for a large group of minerals, hydrous silicates of aluminum and potassium, often containing magnesium, ferrous iron, ferric iron, sodium, and lithium and more rarely containing barium, chromium, and fluorine.
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 (biotite or muscovite). Other schists are hornblende schist, talc schist, chlorite schist, and graphite schists. Schists are abundant in the Precambrian (Archean and Proterozoic) rocks.

schist

[shist]
(geology)
A large group of coarse-grained metamorphic rocks which readily split into thin plates or slabs as a result of the alignment of lamellar or prismatic minerals.

schist

A rock, the constituent minerals of which have assumed a position in more or less closely parallel layers or folia; due to metamorphic action; used principally for flagging.

schist

any metamorphic rock that can be split into thin layers because its micaceous minerals have become aligned in thin parallel bands
References in periodicals archive ?
The lithology of the area consists of greenschists, mica schists, quartzites, hornblende schists, amphibolites, garnet-amphibolites, serpentinites and porphyritic hypabyssal rocks with andesitic to dacitic composition (Figure 1).
In Wadi Sikait, these rocks are represented by phlogopite and actinolite schists in the schist melange.
The only comparison possible is that similar rock surface accretions were sampled from schist in the Coa and that similar radiocarbon results were obtained.
CSDD12_006 was drilled in the south immediately west of outcropping graphite, intersected highly weathered graphitic schist to 21m.
Ruffer reported finding schist some eggs in Egyptian mummies.
This condition is well met in the Coa Valley where the panels on which the art was engraved are created by slabbing along joint planes in schist spaced at approximately 1.
The unique feature of this trench (and not previously recognized in this zone) was the recognition of a series of shallow dipping quartz structures that were generally gold enriched compared to the host schist.
complete 3) Providing & laying apron using dressed schist stone slabs all around the tombs over a concrete base(using 1:3:6) and 20mm.