Gold, chemical element, symbol Au; for physical constants see Periodic Table. Gold has been known and highly valued from earliest times. It is found free in nature and in combination with tellurium. It is recovered from its ores by cyaniding, amalgamating, and smelting. Gold is a soft, yellow, unreactive metal not attacked by common acids. Gold is used in coinage and is a standard for monetary systems in many countries. Gold and its compounds are used for jewelry, decoration, dental work, and plating.