A quartz clock is a clock that uses an electronic oscillator that is regulated by a quartz crystal to keep time. This crystal oscillator creates a signal with very precise frequency, so that quartz clocks are at least an order of magnitude more accurate than mechanical clocks.
The ability to convert voltage to and from mechanical stress is called piezoelectricity. Quartz crystals maintain a precise frequency standard, which helps to regulate the movement of a watch or clock, thus making the timepieces very accurate
