Polymorphous transformation of quartz induced by mechanical treatment

Because of its strongly damaged structure (partially crystalline) mechanically activated α-quartz is not transformed to β-quartz. Rather, mechanically activated α-quartz is rapidly transformed to the cristobalite modification even at temperatures as low as 1200 °C. The acceleration and temperature shift of the quartz-cristobalite transformation is caused by mechanically induced defects. The activation energy of the transformation is thus reduced by about 50%.