GaPO4 is isotypic with quartz, possessing very similar properties, but the silicon atoms are alternately substituted with gallium and phosphorus, thereby doubling the piezoelectric effect.

GaPO4 has many advantages over quartz for technical applications, like a higher electromechanical coupling coefficient in resonators, due to this doubling.

The specific structure of GaPO4 shows the arrangement of tetrahedrons consisting of GaO4 and PO4 that are slightly tilted.

Pressure sensors based on quartz have to be cooled with water for applications at higher temperatures (above 300°C).

For bulk resonator applications, this crystal exhibits temperature compensated cuts of up to 500°C while having Q factors comparable with quartz.