The correct option is B Quartz Quartz crystals have piezoelectric properties; they develop an electric potential upon the application of mechanical stress. An early use of thic property of quartz crystals was in phonograph pickups. One of the most common piezoelectric uses of quartz today is as a crystal oscillator. The quartz clock is a familiar device using the mineral. The resonant frequency of a quartz crystal oscillator is changed by mechanically loading it, and this principle is used for very accurate measurements of very small mass changes in the quartz crystal microbalance and in thin film monitors. THEORY Uses of SiO2:
Quartz is extensively used as a piezoelectric material.
Extremely accurate clocks
Mobile radio communications
Silica gel used as a drying agent and as a support for chromatographic materials and catalysts.
Kieselguhr, an amorphous form of silica is used in filtration plants.