This is used in Thermal Conductivity instruments to differentiate diamond which conducts heat very well from its simulants and imitations. Some instruments use it to identify other gemstones but they are expensive and of value only when used with care and some gemmological knowledge. The use of standard stones is suggested and drafts to be avoided as they can change the readings. At its simplest this is the temperature test using tongue or lips for glass and plastic. Atomic structure and the related crystal structure influence electrical properties.
Some crystals possess pyro-electricity.
Tourmaline for example when heated to between 100 - 100oC possesses polarity like a magnet needle. This is used in piezo-electric gas lighters. If an alternating current is applied to the crystal it oscillates. This is used in controlling radio wavelengths, usually using synthetic quartz. Quartz watches use these properties.