Shock-induced transition of quartz to stishovite.

The transformation of quartz to stishovite has been studied by X-ray and optical examination of a series of experimentally shock-loaded specimens of a quartz-copper mixture. Shock pressures of 68 to 260 kb and peak temperatures of 320 to 870 K were achieved. Stishovite was identified from quartz shock-loaded above 90 kb; the quantity increases with increasing pressure, but is not dependent on temperature. The formation of stishovite under shock conditions appears to be intimately related to a short-range order phase.