Gold
Gold (element #79, symbol Au) is a heavy, shiny yellow metal. It is probably the oldest precious metal known to humans. Wars have been fought over it and countless numbers have died trying to gain it or protect it. Its physical and chemical properties make it ideal for a number of applications. It is used in dentistry and medicine, in jewelry and arts, in medallions and coins, in ingots as a store of value, for scientific and electronic instruments, and as an electrolyte in the electro-plating industry. South Africa has about half of the world’s gold resources. Significant quantities are also present in the U.S., Australia, Brazil, Canada, China, and Russia.
Type
Element (Minerals/Ores of)
Mineral Classification
Native
Chemical Formula
Au
Streak
Shining yellow
Mohs Hardness
2.5-3
Crystal System
Isometric
Color
Gold
Luster
Metallic
Fracture
Jagged
Description
Gold (element #79, symbol Au) is a heavy, shiny yellow metal. It is probably the oldest precious metal known to humans. Wars have been fought over it and countless numbers have died trying to gain it or protect it. Its physical and chemical properties make it ideal for a number of applications. It is used in dentistry and medicine, in jewelry and arts, in medallions and coins, in ingots as a store of value, for scientific and electronic instruments, and as an electrolyte in the electro-plating industry. South Africa has about half of the world’s gold resources. Significant quantities are also present in the U.S., Australia, Brazil, Canada, China, and Russia.
Relation to Mining
Gold is found in two major types of deposits. Lode deposits are where gold is found in veins in rock. The second type is called a placer deposit that is formed by moving water that has eroded gold out of lode deposits. When the speed of the water in a river slows sufficiently, the heavy gold falls to the bottom and accumulates in the sand of the riverbed. Another source of gold is as a by-product of copper and silver mining. Gold is so valuable that it is worth the effort to recover even minute amounts from copper and silver ore.
It is estimated that the total amount of gold yet to be removed from the Earth is 100,000 tons. South Africa is the world’s largest producer of gold and is estimated to have half of these gold resources. The United States and Brazil each have significant amounts of the world’s gold resources. Approximately one-fifth of the total resources of gold in the world are by-products from copper and silver ore processing.
In the United States, Nevada produces the majority of the gold followed by Alaska. The remaining gold deposits are in other western states. Most of the gold recovered in the United States is produced from only about 30 mines. Brazil and Canada export significant amounts of gold to the United States.
Uses
Most gold is used to make jewelry and other art items. Because it is chemically stable and conducts electricity so well, it is very important in electronics. Electronic applications represent a significant amount of the United States’ annual gold consumption, followed by dentistry and a variety of other applications.
Gold has been very important as the standard for currency. In 1792, the United States Congress established gold and silver as the standard for the nation’s money. The U.S. Department of the Treasury holds a major stockpile of gold.
