Gold ( /ˈɡoʊld/) is a chemical element with the symbol Au (from Latin: aurum "gold") and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive solid chemical elements. The metal therefore occurs often in free elemental (native) form, as nuggets or grains in rocks, in veins and in alluvial deposits. Less commonly, it occurs in minerals as gold compounds, usually with tellurium.
A gold coin is a coin made mostly or entirely of gold. Gold has been used for coins practically since the invention of coinage, originally because of gold's intrinsic value. In modern times, most gold coins are intended either to be sold to collectors, or to be used as bullion coins—coins whose nominal value is irrelevant and which serve primarily as a method of investing in gold.
Gold has been used as money for many reasons. It is fungible, with a low spread between the prices to buy and sell. Gold is also easily transportable, as it has a high value to weight ratio, compared to other commodities, such as silver. Gold can be divided into smaller units, without destroying its value; it can also be melted into ingots, and re-coined. The density of gold is higher than most other metals, making it difficult to pass counterfeits. Gold is extremely unreactive. The scarcity of gold stabilizes its value.