The English word "gold" comes from an Anglo-Saxon word "gohl," thought to mean "yellow, green or shiny." The chemical symbol for gold is Au, comes from its Latin name "aurum." Human discovery and use of gold dates to prehistoric times. It is one of the few elements occurring in nature in its pure state.
Gold, as a metal, has a long history of use in jewelry. Under normal circumstances, gold does not corrode. Unlike silver that tarnishes, gold jewelry retains its luster for years. Because pure or 24-karat gold is quite soft, jewelers mix it with other metals, forming alloys, including 14-karat gold and 10-karat gold, to increase its strength before forming into jewelry.
Gold is also malleable. It is possible to form a single ounce of gold into foil, so thin the human eye is able to see through it and larger than a baseball field. Formed into a 1-micrometer diameter wire, the same ounce of gold stretches 2,000 kilometers, while maintaining integrity to conduct an electrical charge.
Pure gold is nontoxic, but is also odorless and tasteless. In 2014, bartenders use gold foil as decoration for expensive mixed drinks and cooks use it to decorate cookies and other foods, a practice that dates back to the Middle Ages.