| Stishovite | |
|---|---|
| Category | Mineral |
| Chemical formula | Silica (silicon dioxide, SiO2) |
| Identification | |
| Color | Clear (if no impurities); also see Varieties |
| Mohs Scale hardness | 9. A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes The Chemical compound silicon dioxide, also known as silica or silox (from the Latin " Silex " is an Oxide The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material 4 |
| Refractive index | nω = 1. The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium 81 |
| Specific gravity | 4. Specific gravity is defined as the ratio of the Density of a given solid or liquid substance to the density of water at a specific temperature and pressure typically 28 when pure |
| Melting point | 1650 (±75) °C |
| Solubility | 11. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. 0 +/- 1. 1 PPM @ 25 C |
| Diaphaneity | Transparent to translucent |
Stishovite (after S. M. Stishov, 20th-century Russian mineralogist) is an extremely hard, dense tetragonal form (polymorph) of silicon dioxide. In Crystallography, the tetragonal Crystal system is one of the 7 lattice Point groups Tetragonal Crystal lattices result from stretching a cubic 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 It was traditionally considered the hardest known oxide; however, boron suboxide was recently discovered to be much harder. Boron suboxide (chemical formula B6O is a solid compound of Boron and Oxygen. At normal temperature and pressure, stishovite is metastable; it will eventually decay to quartz; however, this phase change is slow enough that it has never been observed. Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in Stishovite was first discovered in nature and named by Edward C. T. Chao. 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
Contents |
Synthesis
The only known occurrences of stishovite in nature formed at the very high shock pressures (>100 kbar = 10 GPa) and temperatures (> 1200°C) present during hypervelocity meteorite impact into quartz-bearing rock. A meteorite is a natural object originating in Outer space that survives an impact with the Earth 's surface In the broadest sense the term impact crater can be applied to any depression natural or manmade resulting from the high velocity impact of a projectile with larger body Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere Stishovite may also be synthesized by duplicating these conditions in the laboratory, either isostatically or through shock (see shocked quartz). Shocked quartz is a form of Quartz that has a microscopic structure that is different from normal quartz
See also
- Coesite, a related mineral
References
High-pressure silica polymorphs as hardest known oxides
External links
Coesite is a form ( polymorph) of Silicon dioxide Si[[oxygen O]]2 that is formed when very high pressure (2&ndash3 Gigapascals andDapyx Software network: MP3 Explorer | Ebook Manager | Zenithic