Coesita

The coesite is a polymorph of quartz that originates when it is subjected to high pressure (2–3 gigapascals) and a slightly high temperature (700 °C). Coesite was first created by Loren Coes in 1953. In 1960, Eugene Shoemaker found naturally formed coesite in Meteor Crater in Arizona, which was evidence that the crater must have been formed by a impact. The coesita is denser than the quartz, and a volcano is not powerful enough to produce it. It has only been found in places where meteorites have hit, or where nuclear tests have been done. Therefore, the presence of coesite in rocks is taken as evidence on Earth of a meteorite impact event or an atomic bomb explosion.

The molecular structure of coesite consists of four ring-shaped silicon dioxide. This structure is very stable.