An examination of geological thin sections of the mineral phyllite using polarizing microscopy, as well as providing information on component minerals, can reveal a great deal about how the rock was formed. The rocks in the earth’s crust continuously undergo changes in their composition which leads to formation of other rocks. Phyllite is typically grey in color and has a sheen from tiny grains of mica. In thin section, the microtexture is dominated by muscovite and quartz grains formed during low grade metamorphism and compositional bands that reflect the original sedimentary layering. Phyllite is very abundant metamorphic rock in the word. Phyllite is formed and its mineral constituents are rearranged, based on the type of stress applied to a rock. Phyllite is formed by relatively low-grade metamorphic conditions in the lower part of the greenschist facies.Parent rocks may be only partially reconstituted so that the original mineralogy and sedimentary bedding are partially preserved. Phyllite is an intermediate-grade, foliated metamorphic rock type that resembles its sedimentary parent rock, shale, and its lower-grade metamorphic counterpart, slate.Like slate, phyllite can be distinguished from shale by its foliation, called slaty cleavage, and its brittleness, or fissility. This is how directed pressure affects the shape and size of minerals under the influence of heat and stress. Phyllite is a metamorphic rock which is formed by regional metamorphism of argillaceous sediments since their cleavage arose due to deviatoric stress. Stone dealers call it slate because it's useful for flagstones and tiles. Millions of years ago, shale was exposed to the heat of magma (up to 800 degrees Celsius) and to the pressure of millions of other rocks atop the shale. Whereas slate has a dull surface because its metamorphic minerals are extremely fine-grained, phyllite has a sheen from tiny grains of sericitic mica , graphite, chlorite and similar minerals. Along with Phyllite Formation, also learn about Phyllite composition and transformation in the next section. Q. As nouns the difference between slate and phyllite is that slate is (uncountable) a fine-grained homogeneous sedimentary rock composed of clay or volcanic ash which has been metamorphosed so that it cleaves easily into thin layers while phyllite is (geology) a type of metamorphic rock formed from clay-rich sediments called pelites. When you leave slate ‘in the oven’ for a little longer, it becomes phyllite. Slate is formed when mudrock is buried deep beneath the earth’s surface and exposed to great pressure and temperatures that would make the mercury in your thermometer boil instantly. © copyright 2003-2020 Study.com. As an adjective slate It is foliated, meaning that it has noticeable layers, and splits easily. The slate quarried today started to form during the Lower Palaeozoic era (a period of time defined as between 417 and 545 million years ago); phyllite is older and dates back to the Pre-Cambrian era (over 545 million years ago). what type of rock is phyllite? The term (from the Greek phyllos, leaf, a reference to its characteristic cleavage) was first used by C. F. Naumann in the late 1850s, but the original reference is lost. There are a variety of Phyllite Uses and the Phyllite Reserves are found in many countries around the world. Phyllite has a marked fissility (a tendency to split into sheets or slabs) due to the parallel alignment of platy minerals; it may have a silky sheen on its surfaces due to tiny plates of micas. The aggregate minerals forming the rock are held together by chemical bonds. Phyllite Classification. The minerals are squeezed, stretched and rotated to align in a given direction. Phyllite is considered a foliated metamorphic rock. Phyllite: Phyllite is a stripped rock made of thin bands of quartz, mica, and chlorite. Phyllite. The sheen of phyllite is from microscopic grains of mica, graphite, chlorite and similar minerals that form under moderate pressure. Create your account. Bedrock is extremely old and belongs to the Caledonian chain. Phyllite or “leaf stone”, is a metamorphic rock made of mostly fine grained mica. Phyllite is a metamorphic rock which forms when slate is further metamorphosed until very fine grained white mica attains a preferred orientation. The slaty cleavage of the phyllite is what makes it a foliated rock. The protolith (or parent rock) for a phyllite is a slate. - Law of Superposition, Principles of Original Horizontality & Cross-Cutting Relationships, Ocean Basins: Definition, Formation, Features & Types, Astronomy 101 Syllabus Resource & Lesson Plans, UExcel Earth Science: Study Guide & Test Prep, Praxis Earth & Space Sciences - Content Knowledge (5571): Practice & Study Guide, CSET Science Subtest II Earth and Space Sciences (219): Test Prep & Study Guide, FTCE Earth & Space Science 6-12 (008): Test Practice & Study Guide, Holt Science Spectrum - Physical Science with Earth and Space Science: Online Textbook Help, Physical Geology Syllabus Resource & Lesson Plans, NES Earth & Space Science - WEST (307): Practice & Study Guide, ILTS Science - Earth and Space Science (108): Test Practice and Study Guide, Ohio State Test - Science Grade 8: Practice & Study Guide, Introduction to Earth Science: Certificate Program, Biological and Biomedical Structure composition and texture. Phyllite is composed mainly of tiny grains of mica minerals such as muscovite, or sericite. Its constituent platy minerals are larger than … Phyllite is a type of foliated metamorphic rock created from slate that is further metamorphosed so that very fine grained white mica achieves a preferred orientation. All other trademarks and copyrights are the property of their respective owners. Earn Transferable Credit & Get your Degree, Get access to this video and our entire Q&A library. Compare with: phyllonite You can also know more about Shale and Phyllite Reserves. 21 Table of Contents These samples of phyllite all came from the same quarry in South Carolina. Phyllites and slates are fine-grained metamorphic rocks that may produce very thick saprolite zones (Zauyah, 1986; Felix-Henningsen, 1994).In a tropical environment, the saprolite is composed of fine-grained quartz and sericite aligned according to the original schistosity (Zauyah, 1986; Stoops et al., 1990) (Fig. /fil uyt/, n. a slaty rock, the cleavage planes of which have a luster imparted by minute scales of mica. Meaning of phyllite. At a granular level, rocks are composed of grains of minerals, which, in turn, are homogeneous solids formed from a chemical compound that is arranged in an orderly manner. A defining characteristic is the shiny surface, called phylitic luster caused by the mica particles within the rock. The exact mineral composition and their relative quantities affect the rock’s appearance, for example: chlorite give… This means that is made by exposing another rock to heat and pressure over time. Phyllite is a metamorphic rock which is formed by regional metamorphism of argillaceous sediments since their cleavage arose due to deviatoric stress. Phyllite (above) illuminated with plane-polarized light. Each rock has a unique formation process. It is primarily composed of quartz, sericite mica, and chlorite. How is metamorphic rock dependent on minerals? Question: How is phyllite formed? Rock found in the zone between A and B is non-foliated and fine grained. Phyllite is a fine-grained metamorphic rock with a well-developed laminar structure, and is … The diagram above shows a cross-section through a portion of Earth’s crust. Phyllite is a fine-grained metamorphic rock formed by the low grade metamorphism of fine-grained, sedimentary rocks, such as mudstones or shales. However, phyllite... Our experts can answer your tough homework and study questions. Phyllite Thin Section in Polarized Light. All rights reserved. It's typically a medium-gray or greenish stone, but here sunlight reflects off its finely wavy face. Phyllite (above) as imaged through crossed Phyllite is formed from the advanced metamorphism of slate. Phyllite - Kilmacrenan. Become a Study.com member to unlock this Slate is composed of fine grains of quartz and mica, either muscovite or illite, along with a range of other minerals that frequently include biotite, chlorite, hematite and pyrite. Phyllite is a geologic name. When cracked along its cleavage, the place where the crystalline structure allows for a clean break, the rock has a silky texture with a sheen that sometimes takes on a golden luster. Metamorphic rock. Rocks exhibiting foliation include the standard sequence formed by the prograde metamorphism of mudrocks; slate, phyllite, schist and gneiss. Information and translations of phyllite in the most comprehensive dictionary definitions … The protolith (or parent rock) for phyllite is usually shale or pelite, via slate. In the eastern part, bedrock is overthrusts of phyllite and mica schist. Albite, Alusite, Amphibole, Apatite, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc, Zircon, Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion, Biological Weathering, Chemical Weathering, Mechanical Weathering. Most metamorphic changes caused by. Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles. Phyllite’s protolyth, or parent rock,is shale. It has a corrugated cleavage and easily splits into sheets due to the parallel alignment of platy minerals. Most people chose this as the best definition of phyllite: A green, gray, or red met... See the dictionary meaning, pronunciation, and sentence examples. PHYLLITE. That is, phyllite is a textural rock type, not a compositional one. The northern part of the catchment is dominated by granites. What does phyllite mean? Regional Metamorphism: Definition & Differences, Intrusive Igneous Rock: Definition & Examples, Geological Folds: Definition, Causes & Types, Bowen's Reaction Series: Crystallization Process & Magmatic Differentiation, Detrital & Chemical Sedimentary Rocks: Definition & Differences, Rock Cycle: Igneous, Sedimentary, and Metamorphic Rocks, Unconformities in Geology: Definition & Types, Lithification of Sediments: Definition & Processes, Volcanic vs Plutonic Igneous Rocks: Definition and Differences, Geologic Time Scale: Major Eons, Eras, Periods and Epochs, Geological Faults: Definition, Causes & Types, What is Relative Dating? Formation of Phyllite is explained below: Along with Phyllite Formation, also learn about Phyllite composition and transformation in the next section. Slate has fine clay flakes which is oriented but with the phyllite it has fine grained mica flakes that are oriented. They have a well-developed planar element called cleavage defined by alignment of mica grains and interlayering of quartz-rich and mica-rich domains. Phyllite is a metamorphic form of shale, mudstone, and siltstone. Phyllite has a satiny appearance and waxy texture. [1820 30; PHYLL + ITE1] * * * Fine grained metamorphic rock formed by the recrystallization of fine grained,… The name phyllite is from scientific Latin and means "leaf-stone." Phyllite Phyllite is a fine-grained metamorphic rock formed by the recrystallization of fine-grained, parent sedimentary rocks, such as mudstones or shales. These mineral grains are usually smaller than what can be easily seen with the unaided eye. It formsIt forms when sedimentary rocks are buried and mildly altered by the heat anddirected pressure of regional metamorphism. Sciences, Culinary Arts and Personal Phyllite formation took place millions of years ago. They form through the low-grade metamorphic transformation of clay minerals. Phyllites are formed through low-grade regional metamorphism. At temperatures higher than … These are almost always convergentplate boundary environments involving continental lithosphere.Phyllite forms inareas of regional metamorphism where where beds of sedimentary rocks have beensubjected to moderate heat and compression by the colliding of continentalplates and mountain-building events. Fine-grained quartz and feldspar are often abundant in phyllite. answer! As phyllite weathers it parts along the cleavage planes. When rock undergoes metamorphism the _____ of the rock changes. Composition of Phyllite. Increased pressure. Phyllite is a fined grained metamorphic rock. Its constituent platy minerals are larger than those in slate but are not visible with naked eye. Phyllite is a stripped rock made of thin bands of quartz, mica, and chlorite. These specimens are stacked in a stone yard. Its constituent platy minerals are larger than those in slate but are not visible with the naked eye. A type of metamorphic rock formed during low-grade metamorphism of clay-rich sediments called pelites. phyllitic /fi lit ik/, adj. The overthrust was formed as a … These digital assets are available under a Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Licence. Both slate and phy… Phyllite is a fine grained metamorphic rock that resembles its sedimentary parent rock, shale. Classification of Igneous Rocks: Textures and Composition, Sedimentary Rocks: Definition, Types & Examples, Metamorphism of Rocks: Definition, Process & Influencing Factors, Contact Metamorphism Vs. Services, Classification of Metamorphic Rocks: Texture & Parent, Working Scholars® Bringing Tuition-Free College to the Community. Phyllites are very fine grained rocks with a grain size barely visible in a hand specimen. phyllite is a rock formed from shale. Shale can metamorphose into slate, schist, gneiss or phyllite depending on the degree of heat and pressure. Various kinds of gneiss are common. Definition of phyllite in the Definitions.net dictionary.