Pure gold. The words are captivating. Pure gold is sumptuous and beguiling. But it has limitations for use in jewelry. Throughout history artisans mixed gold with other metals for a variety of reasons, from improving its strength to changing its color.
Pure gold is easy for jewelers to fashion, but it scratches rather easily and is susceptible to wear over time. Alloying pure gold with harder metals like silver, copper or nickel results in a more durable alloy.
Pure silver is lovely and luminous, but too soft and easily damaged to be as versatile as its alloys. Even the silver used to make tableware has been alloyed to improve its hardness and durability.
In order to bear the name “silver”, in the US silver alloys must contain at least 92.5% pure silver and 7.5% copper. The description “nickel silver” has the word silver in it, but it doesn’t describe pure silver or its alloys. In fact “nickel silver” contains no silver at all. It is a combination of base metals- copper, nickel and zinc- that merely resembles sterling silver in color.
Compared to gold and silver, platinum is a relatively recent discovery. Platinum is one of the strongest and most durable of all metals. However, platinum’s physical properties made it a challenge to use in jewelry manufacturing. One of the biggest challenges to early scientists was its very high melting point: approximately 3224 F. Use of the high-heat oxyhydrogen torch finally allowed jewelers to melt and solder platinum in the nineteenth century.