| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 1,804,268,261 visitors served. |
|
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
stishovite |
Also found in: Dictionary/thesaurus, Wikipedia, Hutchinson | 0.03 sec. |
|
stishovite [′stish·ə‚vīt] (mineralogy) SiO2A polymorph of quartz, a dense, fine-grained mineral formed under very high pressure (about 1 × 106pounds per square inch or 7 × 109pascals); it is the only mineral in which the silicon atom has a coordination number of six; specific gravity is 4.28. Also known as stipoverite. How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
|
| ? Mentioned in | ? References in periodicals archive | |
|---|---|---|
Its atoms aggregate in forms as common as quartz crystals and as exotic as coesite and stishovite, minerals formed by the intense pressures generated when extraterrestrial objects such as comets and asteroids strike Earth's surface (SN: 6/15/02, p. Some of these forms -- like stishovite, a phase of quartz produced under extremely high pressure -- are "generally considered indisputable evidence [of an impact] when found near the surface," Melosh says. The discovery of extraterrestrial amino acids (135: 356) and the rare mineral stishovite (135: 132) in rocks from the Cretaceous-Tertiary Boundary provided further evidence that a large body collided with Earth 65 million years ago, causing the mass extinctions that occurred around that time. |
| Encyclopedia |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup | Partner with us |
|---|