Platinum is a member of a suite of similar white or gray colored metals, including platinum, ruthenium, rhodium, osmium, iridium and palladium, and are collectively known as the Platinum Metal Group (PMG). Platinum has been used for thousands of years, but wasn’t considered a distinct metal until 1735. The word platinum is derived from the phrase “platina,” with platina being a derogatory Spanish term for “little silver” in the mistaken impression that the metal was an impure ore of silver. Because of the high melting temperature of platinum, the Spanish did not know how to work with it and did not value it the way they did gold. Native platinum is almost always found in conjunction with iron or other metals, such as iridium, rhodium and palladium. Platinum is generally found in nature in the form of small grains, and rarely as nuggets or crystal.
Platinum gained more interest after the early 1800s, when William Hyde Wollaston and Smithson Tenant discovered a way to refine platinum so that it could be produced commercially. In the 1890s, the French jeweler, Cartier, found that platinum was the perfect metal to express the garland style of jewelry made popular by him. Strong and resistant to oxidation or attacks by acids, platinum could be used effectively in the popular “knife-edge” settings of the delicate Edwardian style jewelry fashionable at the turn of the century. In the Art Deco period of the 1920s and 1930s, platinum overtook gold as the preferred metal for showing off the popular diamond styles of the day, and was only usurped by gold at the beginning of World War II, when platinum was declared a strategic metal and the U.S. government banned its use for anything other than military applications. Following World War II, platinum gained some of its popularity back when used for the light and airy designs of Harry Winston, where the smallest amount of metal was used to show gemstones more prominently and the settings needed to be strong. But, generally, until the early 1990s, white gold was more acceptable to the American public because it was less expensive. In the early 1990s, platinum again became highly fashionable in America due in part to the formation of Platinum Guild USA (PGI); a marketing and information group that offered technical training to jewelers in order to promote the positive aspects of this beautiful metal.
Today platinum is generally mixed with ruthenium, iridium or palladium to make it less brittle, and to extend the amount of the precious material as much as possible. Popular alloys of platinum include 950 platinum, composed of 95 parts of platinum to 5 parts of ruthenium, which has become a popular formula for cast and die-struck platinum. In the 1920s and ‘30s, 90% platinum to 10% iridium was a popular alloy. Platinum jewelry is generally stamped "PLAT," "PLAT 950," "PLAT 900," "Pt 950" or "Pt 900," or "10% Irid. 90% Plat.," depending upon the alloy being used.
The largest known reserves of platinum occur in the Bushveld complex in South Africa. Russia, Canada and, to a lesser extent, the U.S. and Colombia also contain significant deposits.
Chemical Symbol: Pt
Crystal System: Cubic
Specific Gravity: 21.4
Hardness: 4 – 4 ½
Color: whitish-Gray Melting Point: 1,773.5 degrees Celsius