Coesite is a form (polymorph) of silicon dioxide SiO₂ that is formed when very high pressure (2–3 gigapascals) and moderately high temperature (700 °C) are applied to quartz. Polymorphism in Materials science is the ability of a solid material to exist in more than one form or Crystal structure The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in Coesite was first created by Loring Coes, Jr. in 1953. Year 1953 ( MCMLIII) was a Common year starting on Thursday (link will display full calendar of the Gregorian calendar. In 1960, coesite was found Edward C. T. Chao^[1], in collaboration with Eugene Shoemaker, to naturally occur in the Barringer Crater, which was evidence that the crater must have been formed by an impact. Year 1960 ( MCMLX) was a Leap year starting on Friday (link will display full calendar of the Gregorian calendar. Edward C T Chao (Edward Ching-Te Chao ( November 30, 1919  &ndash February 3, 2008) was one of the founders of the field of impact Eugene Merle Shoemaker (or Gene Shoemaker ( April 28, 1928  &ndash July 18, 1997) was one of the founders of the fields of Planetary Meteor Crater is a Meteorite Impact crater located approximately 43 miles east of Flagstaff, near Winslow in the northern

The presence of coesite in unmetamorphosed rocks may be evidence of a meteorite impact event or of an atomic bomb explosion. See also Impact crater An impact event is the Collision of a large Meteoroid, Asteroid or Comet (generically A nuclear weapon is an explosive device that derives its destructive force from Nuclear reactions either fission or a combination of fission and fusion. In metamorphic rocks, coesite commonly is one of the best mineral indicators of metamorphism at very high pressures (UHP, or ultrahigh-pressure metamorphism)^[2]. Such UHP metamorphic rocks record subduction or continental collisions in which crustal rocks are carried to depths of 70 km or more. Coesite also has been identified in eclogite xenoliths from the mantle of the earth that were carried up by ascending magmas; kimberlite is the most common host of such xenoliths. Eclogite (ˈɛklədʒaɪt is a coarse-grained Mafic ( Basaltic in composition Metamorphic rock. Kimberlite is a type of potassic Volcanic rock best known for sometimes containing Diamonds It is named after the town of Kimberley in South Africa

The molecular structure of coesite consists of four silicon dioxide tetrahedra arranged in a ring. A tetrahedron (plural tetrahedra) is a Polyhedron composed of four triangular faces three of which meet at each vertex. The rings are further arranged into a chain. This structure is metastable within the stability field of quartz: coesite will eventually decay back into quartz with a consequent volume increase, although the metamorphic reaction is very slow at the low temperatures of the Earth's surface. Metastability is a general scientific concept which describes states of delicate equilibrium A metamorphic reaction is a Chemical reaction that takes place during the Geological process of Metamorphism in an amalgamate of Minerals that

See also

• List of minerals
• List of minerals named after people
• Stishovite, a related mineral

External links

• Coesite page
• Barringer Meteor Crater science page

References

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