what elements are contained in both feldspar and quartz ! please answers !
Google around for piezoelectric effect and pyroelectric effect and thermocouple.
Some crystals are pyroelectric, which means that if the crystal (sliced in a particular crystallographic orientation) is heated up, it causes the crystal structure to deform and become an electric dipole (become electrically charged). I'm not sure if quartz has this property - it might. Quartz DOES have another similar property called piezoelectricity. When a quartz crystal (sliced in a particular crystallographic orientation) is compressed (physically deformed) it causes the crystal structure to deform and become electrically charged. Conversely, if an electric charge is applied to the crystal it will deform in a particular way, vibrating at a known frequency. Tourmaline also has both of these properties.
