How is Coesite formed?
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, 1,300 °F), are applied to quartz. Coesite was first synthesized by Loring Coes Jr., a chemist at the Norton Company, in 1953.
What is Coesite and stishovite?
Coesite inverts rapidly to lower-density forms of silica at temperatures above 350°C and pressures below 1 atm. Stishovite begins to invert to lower-density forms at temperatures of 1000°C and a pressure of 30,000 atm; hence, it is virtually impossible that stishovite could survive transport to the surface.
What is Coesite used for?
Uses: As an indicator of high pressure crystallization (possibly a meteorite impact) and as mineral specimens.
Is Coesite a rock or mineral?
Coesite is a very rare mineral that forms in unique ultra high metamorphism usually as a result of meteorite impacts. It was named after American chemist Loring Coes, Jr. (1915-1978), who first synthesized Coesite in 1953 before it was naturally discovered in Barringer Crater in 1960.
What type of mineral is Coesite?
Coesite, a high-pressure polymorph (crystal form) of silica, silicon dioxide (SiO2). It has the same chemical composition as the minerals cristobalite, stishovite, quartz, and tridymite but possesses a different crystal structure.
How do you identify coesite?
About CoesiteHide
- SiO2
- Colour: Colourless, very pale pink, very pale yellowish-white.
- Lustre: Vitreous, Sub-Vitreous, Waxy.
- Hardness: 7½ – 8.
- 2.92 (Calculated)
- Monoclinic.
- Name: For Loring Coes Jr.
- Type Locality: ⓘ Meteor Crater (Barringer Crater), Meteor Crater area, Coconino County, Arizona, USA.
What is the mineral coesite?
coesite, a high-pressure polymorph (crystal form) of silica, silicon dioxide (SiO2). It has the same chemical composition as the minerals cristobalite, stishovite, quartz, and tridymite but possesses a different crystal structure.
What kind of mineral is Stishovite?
Stishovite was named after Sergey M. Stishov, a Russian high-pressure physicist who first synthesized the mineral in 1961. It was discovered in Meteor Crater in 1962 by Edward C. T….
| Stishovite | |
|---|---|
| Crystal structure of stishovite | |
| General | |
| Category | Tectosilicate, quartz group |
| Formula (repeating unit) | SiO2 |
Is coesite a rock or mineral?
Where was the coesite found in the Earth?
Because of the very high pressure necessary for its formation, it does not occur naturally in the Earth’scrust. Artificially produced in 1953 by the American chemist Loring Coes, Jr., it was discovered in nature in 1960 in the sandstone on the floor of Meteor Crater, near Winslow, Ariz.
What kind of crystal is a coesite Crystal?
Both quartz and coesite are polymorphs with all the members of the Quartz Group which also include cristobalite, tridymite and stishovite . Well formed crystals are very rare as coesite does not usually get much time to form crystal faces.
Is the mineral coesite the same as cristobalite?
Coesite, a high-pressure polymorph (crystal form) of silica, silicon dioxide (SiO 2 ). It has the same chemical composition as the minerals cristobalite, stishovite, quartz, and tridymite but possesses a different crystal structure. Because of the very high pressure necessary for its formation, it does not occur naturally in…
How is coesite formed from silicon dioxide SiO2?
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, 1,300 °F), are applied to quartz.