Source: American Museum of Natural History:
•It has been estimated that, worldwide, the total amount of gold ever mined is 152,000 metric tons, only enough to fill 60 tractor trailers. In comparison, each year 907 million metric tons of iron are produced worldwide. This is equivalent to 6,000 times the total gold produced throughout history.
•All the gold that has ever been refined throughout history could be placed in a cube measuring 65.5 feet (20 meters) on a side.
•More than 90 percent of all gold ever used has been mined since 1848, when gold was discovered at Sutter’s Mill, California, sparking the greatest gold rush of all time.
•Gold nuggets are solid lumps of gold. Nuggets are rare, making up less than 2 percent of all native gold ever mined.
•Only one out of a billion atoms of rock in Earth’s crust are gold. (If expressed by weight abundance, it is five parts per billion, but by numbers of atoms it is about one atom of gold per billion.)
•Oceans are the greatest single reservoir of gold at Earth’s surface, containing approximately eight times the total quantity of gold mined to date. However, the current cost of extracting it is more than the gold is worth.
•Gold is so malleable that a single ounce of it (about the size of a quarter) can be beaten into a thin continuous sheet measuring roughly 100 square feet. That means it would take 576 ounces (or just 36 pounds) of gold to completely cover a football field, or a whopping 367,211 ounces (or about 11 tons) of gold to completely blanket all of Central Park.
•One ounce of gold can be stretched into a thin wire measuring only five microns, or five millionths of a meter, thick, that would reach in a straight line from midtown Manhattan across Long Island Sound to Bridgeport, Connecticut–a distance of 80 kilometers or 50 miles.
•Nearly 40 percent of all gold ever mined was recovered from South African rocks.
•Gold leaf may be only 0.18 microns (seven millionths of an inch) thick; a stack of 7,055 sheets would be no thicker than a dime.
•The visors of astronauts’ space helmets receive a coating of gold so thin (0.00005 millimeters, or 0.000002 inches) that it is partially transparent. The astronauts can see through it, but even this thin layer reduces glare and heat from sunlight.
•Most gold–78 percent of the yearly gold supply–is made into jewelry. Other industries, mostly electronics, medical, and dental, require about 12 percent. The remaining 10 percent of the yearly gold supply is used in financial transactions.
