Abstract A technique for the toroidally symmetrical implosion of non-metallic solids has been developed, and satisfactory recovery of shocked materials achieved. A procedure to quench a heat-sensitive high-pressure phase produced by a pressure pulse has been demonstrated. New examples of shock-induced phase changes have been found in the reconstructive transitions litharge → massicot,β → α lead dioxide, and cadmium sulfide (wurtzite → zincblende via the sodium chloride structure). A shock-induced ionic displacement transition has been observed in calcite → aragonite. By analogy with static experiments involving shear it is concluded that both types of phase transitions obtained here by the converging shockwave technique take place by a shear mechanism.