For more than 6,000 years, people have cherished and fought over gold,
and this metal was responsible in part for the making of civilization. Gold
is the universally accepted medium of exchange. It is also a status symbol,
and down through the ages people have adorned their bodies with this
metal regardless of its great weight. Along with diamonds, gold is
exchanged during marriage ceremonies in most parts of the world. Gold is
even believed to have healing powers. People in Japan seek its medicinal
powers by bathing in a tub fashioned into a shape of a phoenix made from
400 pounds of pure gold.
Gold does not tarnish and resists corrosion; gold coins recovered from
sunken treasure ships that have lain on the bottom of the ocean for centuries
look as bright as new. Gold is extremely malleable, and a single ounce can be
beaten into a sheet covering nearly 100 square feet. Visitors to Bangkok,
Thailand, are often awestruck by the apparent abundance of gold spread on
the roofs of temples and other buildings until one realizes how extremely thin
gold gilding can be made. Even glass coated with a thin film of gold can reflect
the summer’s sun and retain a building’s heat during the winter to cut down
on utility costs.
The California gold rush began in early 1848 with the discovery of
gold at John Sutter’s sawmill near present-day Sacramento. Word spread
like wildfire, and Californians headed for the hills to mine gold. They
were soon joined by get-rich-quick men from other parts of the country,
who stormed into California from all directions. Several thousand poorly
equipped fortune hunters died along the way, most from disease, famine,
and cold. Mining camps sprang into shantytowns, where miners lived
under primitive conditions and claim disputes and drunken brawls were
common. Supplies had to be paid for in gold dust, and prices were exorbitant.
Of the many thousands who went into the mountains to dig for gold,
only a few actually got rich, most of whom did so by mining the pockets
of other miners.
The gold-bearing veins of the foothills of the western Sierra Nevada
Range in California are usually steeply inclined ledges dipping
down into the granite roots of the mountains. The hydrothermal
veins of the Mother Lode system trend north-south, covering a distance
of some 200 miles. The veins are composed of a hard, milky white
quartz, generally no more than three feet wide. The quartz might have
a few specks of gold and pyrite (fool’s gold) sprinkled throughout, but
seldom did stringers of pure gold shoot through the veins. Most miners
panned for gold out of the sands and gravels that washed down from the
mountains.
Gold has a specific gravity or density of about 19, making it roughly
eight times heavier than ordinary sands and gravels. Therefore, if gold
sands are placed in suspension with water by vigorous swirling or sluicing,
the gold falls out of the mixture and onto the bottom of a gold pan
or sluice box. This technique is known as placer mining, and
for this type of mine to be profitable, many tons of sand and gravel along
with large quantities of water have to be processed. An individual panning
for gold will most likely not get rich, but at the present price of around
$300 a troy ounce (12 ounces per pound), he or she might possibly find
enough to pay for provisions with a little left over. The forty-niners rarely
did so.
The gold rush was not confined to California but headed eastward
into Wyoming, Colorado, New Mexico, and Nevada. The gold of Carlin,
Nevada, is an oddity, however. The gold flakes are so small they cannot
be seen even with most microscopes. Yet those tiny specks add up to at
least 85 million ounces, making the area the world’s third-largest gold producing
region. The gold boiled up in the same hot magma plume or hot
spot that gave rise to Yellowstone National Park. Along its way to its present
location, the hot spot left a trail of basins, volcanoes, and geysers from
Nevada, across Idaho, and into Wyoming. About 40 million years ago, the
hot spot rested underneath Carlin, where gases and water saturated with
gold shot up toward the surface.
Perhaps the most spectacular mining episodes and mines with the most
colourful names were located in the Colorado Mountains,
which are peppered with old abandoned mining camps, attesting to the many
thousands who had more gold in their eyes than they found in the ground.
When the underground mines played out, gold dredging techniques were
developed. Some of the old mining towns eventually became ski
resorts, gambling destinations, and tourist attractions; many more became
ghost towns with only a few remnants to mark the past.
Silver is often associated with gold, and the Comstock Lode in Nevada
was the scene of one of the largest mining booms in the history of the opening
of the American West. Although silver was originally discovered in 1859, production
did not peak until the 1870s.Many mines were scattered along a three mile
mineralized fault zone that separated young volcanic rocks from older
rocks. The lode forms a slab, inclined about 40 degrees to the horizontal, and
reaches a thickness of 400 feet and a depth of 3,000 feet below the surface. The
silver combines with sulphur to make simple silver minerals such as argentite, with
a nearly 3 percent gold content, which helped make mining more profitable.
The gold and silver mines in South America were responsible in large
part for the Spanish settlement there shortly after Columbus discovered the
Americas. Natives of the Inca Empire, which stretched halfway down the
Andes Mountains, extending some 3,000 miles from Colombia to Argentina,
mined gold and silver out of eroded stumps of ancient volcanoes. Cerro Rico
("hill of silver") in Bolivia is a 15,000-foot volcano that was literally
shot through with veins of silver.
When the Spanish conquistadors first landed in Peru in 1532, they
found the Inca Empire torn apart by civil war. The Spaniards had little trouble
taking over the empire and captured a great deal of gold and silver along
with masterpieces of Inca goldsmiths, which they melted into bullion and sent
on to Spain. Some Spanish galleons, heavily loaded with gold and silver, were
lost during storms at sea, and today their precious cargoes are eagerly sought
after by undersea treasure hunters.