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Precious Metals

History, Gold, Occurrence, Placer Gold, Gold Veins, Production And Uses, SilverFuture outlook

Gold, silver, and platinum have historically been valued for their beauty and rarity. They are the precious metals. Platinum usually costs slightly more than gold, and both metals are about 80 times more costly than silver. Precious metal weights are given in Troy ounces (named for Troyes, France, known for its fairs during the Middle Ages) a unit approximately 10% larger than 1 oz (28.35 g).

The ancients considered gold and silver to be of noble birth compared to the more abundant metals. Chemists have retained the term noble to indicate the resistance these metals have to corrosion, and their natural reluctance to combine with other elements.


Because of their rarity and unique properties, the demand for gold and platinum are expected to continue to increase. Silver is more closely tied to industry, and the demand for silver is expected to rise and fall with economic conditions.

See also Element, chemical; Mining.


Resources

Books

Boyle, Robert. Gold History and Genesis of Deposits. New York: Van Nostrand Reinhold, 1987.

Kesler, Stephen. Mineral Resources, Economics and the Environment. New York: MacMillan, 1994.

Klein, C. The Manual of Mineral Science. 22nd ed. New York: John Wiley & Sons, Inc., 2002.

St. John, Jeffrey. Noble Metals. Alexandria, VA: Time-Life Books, 1984.


Eric R. Swanson

KEY TERMS

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Catalyst

—Any agent that accelerates a chemical reaction without entering the reaction or being changed by it.

Electrum

—A natural alloy of gold and silver.

Hydrothermal fluid

—Hot water-rich fluid capable of transporting metals in solution.

Malleable

—the ability of a substance to be pounded into thin sheets or otherwise worked, for example during the making of jewelry.

Placer

—A mineral deposit formed by the concentration of heavy mineral grains such as gold or platinum.

Specific gravity

—The weight of a substance relative to the weight of an equivalent volume of water; for example, basalt weighs 2.9 times as much as water, so basalt has a specific gravity of 2.9.

Troy ounce

—The Troy ounce, derived from the fourteenth-century system of weights used in the French town of Troyes, is still the basic unit of weight used for precious metals.

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