Aside from quartz, another substances that exhibit the piezoelectric effect are Rochelle salt and tourmaline. Rochelle salt displays the best piezoelectric result, but its applications are restricted to manufacture of microphones, headsets and loudspeakers. It can be since the Rochelle salt is mechanically the weakest and strongly impacted by moisture https://consumer-electronics-crys49505.tkzblog.com/34739104/the-5-second-trick-for-timing-components-for-consumer-electronics