Dense, high-pressure phase of Composed of SiO2, quartz is one of the silica group minerals most common in Earth's crust, but never found in meteorites as inclusions visible to the naked eye. Quartz in meteorites has been found in very small quantities in eucrites, other calcium-rich achondrites, and in the highly reduced E chondrites1. Click on Term to Read More; so far identified only in shock-metamorphosed, quartz-bearing rocks from Work in progress. A solid natural object reaching a planet’s surface from interplanetary space. Solid portion of a meteoroid that survives its fall to Earth, or some other body. Meteorites are classified as stony meteorites, iron meteorites, and stony-iron meteorites. These groups are further divided according to their mineralogy and Click on Term to Read More impact craters. Stishovite was synthesized in 1961 before it was discovered at How long Sonic booms Of the several 10s of tons of cosmic material entering Earth's atmosphere each day, only about one ton reaches the surface. An object's chance of survival depends on its initial mass, speed and angle of entry, and friability (tendency to break up). Micrometeoroids radiate heat so Click on Term to Read More Bowl-like depression ("crater" means "cup" in Latin) on the surface of a planet, moon, or asteroid. Craters range in size from a few centimeters to over 1,000 km across, and are mostly caused by impact or by volcanic activity, though some are due to cryovolcanism. Click on Term to Read More, Arizona. Its structure consists of parallel chains of single SiO6 octahedra. The octahedra are on their sides, sharing opposing edges.
Image source: http://www.auburn.edu/~hameswe/Stishovitepage.html.
stishovite is believed to have formed only due to the high pressures generated by a meteorite impact. The discovery of stishovite in a K/T boundary clay has been used as convincing evidence of a meteorite impact at the time of the K/T boundary. http://www.science.smith.edu/geosciences/min_jb/SilicaPolymorphs.pdf