Shock-Induced Luminescence in Quartz

Crystalline quartz shocked parallel to the X axis was luminescent at pressures greater than 30 and 40 kbar in the −X and +X orientations, respectively. Fused quartz and crystalline quartz shocked parallel to the Y and Z axes exhibited practically no luminescence at pressures below 120 kbar. From consideration of (1) the almost instantaneous appearance of the light patterns, (2) a comparison of the electrical results of Neilson, Benedick, and Graham with the luminescence, and (3) sodium present in the quartz, it is suggested that luminescence in quartz shocked parallel to the X axis is caused by the combined effects of piezoelectric voltage and shock compression. The light observed in crystalline quartz shocked parallel to the Y and Z axes and in fused quartz is attributed to triboluminescence.