A quartz crystalQuartz Crystal A quartz crystal is a piece of quartz that has been cut and shaped to vibrate at a specific frequency when an electric current is applied to it. This frequency is known as the resonant frequency, and is determined by the crystal's size and shape. The quartz crystal oscillates at this precise frequency and generates a very stable electrical signal, which is used to keep time in quartz watches. The quartz crystal is placed in a circuit, called the oscillator circuit, that uses the electrical signal to drive the watch's motor, which moves the watch's hands. [Learn More] is a piece of quartz that has been cut and shaped to vibrate at a specific frequency when an electric current is applied to it. This frequency is known as the resonant frequency, and is determined by the crystal’s size and shape. The quartz crystal oscillates at this precise frequency and generates a very stable electrical signal, which is used to keep time in quartz watches. The quartz crystal is placed in a circuit, called the oscillator circuit, that uses the electrical signal to drive the watch’s motor, which moves the watch’s hands.