The Rush to Gold
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The Rush to Gold 1 he modern world's quest for gold brought panicked rushes and get-rich-quick schemes, and eventually extended mining efforts to a scale unprecedented in earlier times. Gold is found in many widespread areas, but South Africa is the world's greatest gold-producing region, with major "gold reef" deposits in the Transvaal and the Orange Free State. North America's most extensive gold area is the Canadian Precambrian shield, which contains the Kirkland Lake and the Porcupine gold fields. Canada has also seen important gold strikes in the Yukon River area below Dawson and in the Northwest Territories around Yellowknife. An extensive gold belt reaches from California to Alaska along the Pacific coast in the United States, though the Black Hills in South Dakota has been one of the country's largest gold producers since 1879. Other important gold-producing areas include Russia, Brazil, and Australia. Approximately 60% of the world's gold reserves are held by governments in their central banks as a significant way to make international payments and to back paper currencies. Gold has a very high electrical conductivity (71% that of copper and 71% that of silver), which, in addition to its resistance to corrosion, makes it a valuable material for plating contacts, semiconductor systems, printed circuits, and terminals. Gold is often used to coat the grids in electron tubes. Gold-silver or gold-nickel alloys are frequently used in the manufacture of electrical contacts, and platinum may be added to provide additional hardness. Since many gold-nickel or goldiron alloys are magnetic, they are used in computer memory systems, such as ferrite memory cores or thin permalloy films. Gold is used as a coating for special infrared mirrors on satellites and spectroscopes, and on spacesuit helmets, reflecting up to 98% of incident irradiation. With the discovery of the New World,
MRS BULLETIN/APRIL 1994
a huge influx of gold—frequently obtained by looting native temples, palaces, and graves—unbalanced the economic structure of Europe in the 16th century. The American gold boom used slave labor drawn from captive Native Americans and workers brought over from Africa. Between 1492 and 1600, 35% of the world's gold production (8 million ounces or 250 million grams) came from South America. In the 17th and 18th centuries, South American mines, especially in Colombia, accounted for 61-80% of the world's gold production. The greatest gold boom occurred from 1850 to 1875. That quarter century alone produced more gold than in the previous 350 years. A smaller gold rush had occurred in Georgia (United States) in 1828-1830, but it was the discovery of gold at Sutter's Mill in California in 1848 that sparked a swarm of treasure seekers from across the United States and the world (including China!) to abandon their families and businesses to chase after the hint of gold in a far-off land. During the winter of 1847-1848, John Augustus Sutter contracted to have a sawmill built on the Sacramento River in California. During the const
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