Images
Formula: SiO2 simple oxide, rutile group
Stishovite is an ultra-high pressure paramorph of
quartz
Specific gravity: 4.28 to 4.35
Hardness: 7¾ to 8
Colour: Colourless
Solubility: Insoluble in common acids and only very slowly soluble in HF
Environments:
Impact zone of a meteorite
Stishovite formed from quartz through high transient shock pressure and
high temperature, in
the impact craters of
large meteorites, where it is found as microscopic grains. Also in ultra-high pressure rocks.
Alteration
Stishovite is a very high pressure paramorph of
quartz. With increasing pressure,
coesite alters to stishovite at about 90 kbar, and at about 2,770oC and
110 kbar pressure, coesite, stishovite and the silica melt
are in equilibrium
(QP).
Back to Minerals