Introduction. During the Cuban Missile Crisis, leaders of the U.S. and the Soviet Union engaged in a tense, 13-day political and military standoff in October 1962 over the installation of nuclear-armed Soviet missiles on Cuba, just 90 miles from U.S. shores.
Base Metal. Base metal is a jewelry industry term for nonprecious metals used in costume jewelry, including copper, aluminum, brass, nickel silver, pewter and white metal, also called pot metal. Nickel silver is a silvery-white alloy resembling silver made from nickel, zinc, copper, iron, manganese and sometimes lead.nlike fine jewelry, costume jewelry is made from nonprecious metals called base metals. Most of these are both beautiful and relatively benign. However, nickel can cause an allergic reaction, while the lead found in some alloys has been linked to far more serious conditions and is highly regulated.
Pure gold is too soft to be used in everyday jewelry, so it is alloyed with other metals to make it stronger and more durable. Pure gold is 24 karat, and 14 karat gold refers to an alloy of gold that contains at least 58.3% pure gold by weight. The balance is made up of other metals to give it strength. Gold is often alloyed with copper, silver, and zinc. Copper is ductile and hard, but tends to tint the alloy pink and is prone to oxidizing.