Some 70 million tons of gold are in solution in the ocean, and perhaps another 10 billion tons of gold lie irretrievable on the ocean floors. Gold is one of the heaviest and most indestructible metals. A cubic inch of gold can be drawn into a continuous wire 43 mi. Because of these properties, more than 30 tons of gold are used each year in electronics to make components, diode plugs, printed circuits, etc. These electroplated applications are less than 0.00005 in. thick.
Gold makes thin corrosion-resistant connections.
The elements most commonly alloyed with gold are copper, silver, zinc, and nickel, in that order. Gold serves many medical purposes. Gold salts are sometimes injected into the muscles to relieve arthritis, gold leaf is used as a surgical dressing because it adheres so well to the shape and depressions of tissues, and gold dental fillings are extremely long-lasting.