Gold is used as jewelry, as currency, as dental fillings, and for eye and ear implants. In addition, gold is used for painting, gilding and lettering. Gold is also used in electronics and in soldering and electroplating. It can also be made into very thin foil and wire and is used to coat space satellites and telescope lenses.
Nanotechnology also finds uses for gold. As it is largely inert, gold is edible, and some expensive restaurants serve meals sprinkled with gold flakes. Gold is a component of goldwasser, an alcoholic beverage. A gold compound is used to treat arthritis, and an isotope of gold is used in cancer treatment.
Gold is very ductile and malleable. Ductile means it can be stretched into thin wires, while malleable means it can be beaten into extremely thin sheets.
Gold is very soft, so when it's used as jewelry, it's alloyed with other metals like nickel, copper, or silver. These added metals not only make the gold tougher, they change its color. Rose gold, for instance, is gold alloyed with copper.
Until the late 20th century, many countries based their monetary systems on a set amount of gold. In this system, paper money could be readily converted into gold.