Quartz is a natural crystal found in nature. It is crystalline form of silicon dioxide, SiO2. Sand is mainly consisted of silicon dioxide.
Quartz has many applications in science and technology. It is used to produce microphones and earphones and very precise oscillators. Quartz is used in oscillators of battery driven watches for great accuracy.
Quartz watches are extremely accurate and keep time with a monthly tolerance of just a few seconds.
Synthetic and extra-pure form of quartz is used in industry to produce very accurate circuitry and equipment.