Throughout history, jewelers and goldsmiths have selected gold as their precious metal of choice because of its unique properties. Gold is naturally beautiful and resists corrosion and tarnishing. It is also soft and malleable, which allows artists to shape the metal into almost any design. Most jewelry is still made that way -- by individuals using craft skills and simple tools that have been around for centuries. Factory production of gold jewelry, however, is becoming more common.
Electronics manufacturers also use gold extensively to take advantage of its high conductivity. Gold conducts electricity better than all other metals except silver and copper. And it doesn't corrode easily. This makes the metal an ideal choice for plating contacts, terminals, printed circuits and semiconductors. A typical computer, for example, uses gold in both the display and the circuit board. Each computer holds only a small amount -- less than 0.1 kilograms (3.5 ounces) of a 27-kilogram (60-pound) machine [source: SWICO Recycling] -- but the numbers add up. According to the U.S. Geological Survey, one metric ton (1.1 tons) of circuit boards can contain 40 to 800 times the amount of gold contained in gold ore mined in the U.S. [source: Grossman].
Other industries that rely on computers and microelectronics, such as aerospace, use large amounts of gold. According to the World Gold Council, NASA used more than 40.8 kilograms (90 pounds) of gold in the construction of the Columbia space shuttle. Much of it found its way into electrical contacts and circuit boards, but a large amount was used in thin-film applications. Sheets of gold 0.15 millimeters (0.006 inches) thick are highly reflective and make effective radiation shields. Similar gold films are now being used to coat the windows of large office buildings, deflecting the sun's rays and controlling passive heating.
Other industries have founds ways to put gold to work, too.
- Health care: Dentists use gold for crowns, and certain medicines, such as sodium aurichloride for rheumatoid arthritis, also contain gold.
- Food and beverage: Small amounts of gold sometimes brighten foods such as jelly or liqueurs, like Goldschläger.
- Chemicals: Gold can catalyze, or speed up, certain chemical reactions more efficiently than other toxic catalysts.
- Environment: Gold can play a role in reducing pollution. For example, scientists have recently discovered that gold particles energized by the sun can destroy volatile organic chemicals.