Look up: cristobalite

1. cristobalite
   [n] - a white mineral consisting of silica
   Found on http://www.webdictionary.co.uk/definitio
   
   
2. cristobalite
   noun a white mineral consisting of silica; found in volcanic rocks
   Found on http://wordnetweb.princeton.edu/perl/web
   
   
3. cristobalite
   the stable form of silica (silicon dioxide, SiO2) between its melting point of 1,728° C (3,142° F) and 1,470° C (2,678° F), below which tridymite is ... [2 related articles]
   Found on http://www.britannica.com/eb/a-z/c/159
   
   
4. Cristobalite
   Cristobalite is a polymorph of trigonal quartz present in many siliceous volcanic rocks as a lining in cavities. Upon heating to 1470 C it becomes nearly transparent. On cooling it assumes its initial white translucent appearance. It has the formulae SiO2 and a relative hardness of 7. Cristobalite w...
   Found on http://www.probertencyclopaedia.com/brow
   
   
5. Cristobalite
   The mineral `cristobalite` is a high-temperature polymorph of silica, meaning that it has the same chemical formula, SiO₂, but a distinct crystal structure. Both quartz and cristobalite are polymorphs with all the members of the quartz group which also include coesite, tridymite and...
   Found on http://en.wikipedia.org/wiki/Cristobalit