Hammered gold. Sample of a thin sheet of hammered gold. Gold (chemical symbol: Au) is a bright yellow precious metal that is heavy, fairly soft and malleable, capable of being hammered into shape. It is a good conductor of heat and electricity; it is used in microscopy and as a radiation source in nuclear medicine; the main use of gold is as a monetary standard and in jewelry. Gold occurs typically as small particles in quartz but also as deposits and sometimes as nuggets. To reach the purity seen here, gold is put through a refining process.