Noun
English Wikipedia has an article on:stishoviteWikipedia
stishovite (usually uncountable, plural stishovites)
(mineralogy) A fine-grained mineral, of SiO2, that is a polymorphic form of quartz formed under very high pressure.
In very high-pressure situations, silicon will be six-fold or octahedral coordination, such as in the perovskite structure or the quartz polymorph stishovite (SiO 2 ). Source: Internet
With the exception of stishovite and fibrous silica, all of the crystalline forms involve tetrahedral SiO 4 units linked together by shared vertices in different arrangements. Source: Internet