Piezoelectricity

A crystal of quartz was found to generate an electric potential when subjected to pressure, a phenomenon known as piezoelectricity. If, in reverse, the crystal was subjected to electricity, it would compress as though under pressure, discovering a way to produce ultrasonic vibrations. This led to microphones and record players.
 Pierre Curie France 1880 Piezoelectricity

A crystal of quartz was found to generate an electric potential when subjected to pressure, a phenomenon known as piezoelectricity. If, in reverse, the crystal was subjected to electricity, it would compress as though under pressure, discovering a way to produce ultrasonic vibrations. This led to microphones and record players.