During the 1970s, the "quartz watch" burst onto the scene as the newest high-tech gadget. Initially, these watches had red LED displays and they cost around $500 in the United States. Since then, the quartz watch has evolved so that either an LCD or a traditional mechanical (hour and minute hand) movement displays the time, and the price has fallen dramatically. It is not uncommon to find quartz watches given away for free in boxes of cereal!
Have you ever wondered why it is called a quartz watch? Or why quartz watches are so much more accurate than wind-up watches?

Modern quartz watches now use a low-frequency bar or tuning-fork-shaped crystal. Often, these crystals are made from thin sheets of quartz plated like an integrated circuit and etched chemically to shape. The major difference between good and indifferent time keeping is the initial frequency accuracy and the precision of the angle of cut of the quartz sheet with respect to the crystalline axis. The amount of contamination that is allowed to get through the encapsulation to the crystal surface inside the watch can also affect the accuracy.
The electronics of the watch initially amplifies noise at the crystal frequency. This builds or regenerates into oscillation -- it starts the crystal ringing. The output of the watch crystal oscillator is then converted to pulses suitable for the digital circuits.