As a precious metal Platinum was first introduced after close to the end of the 19th century. The main characteristics of platinum are its deep luster and a vivid white color. Platinum is much more valuable than pure gold or palladium. Platinum is often used to produce the finest jewelry and for setting expensive gemstones. Platinum is one of the most popular metals of choice for ring settings, because the strength and color of platinum magnifies the brilliance and depth of diamonds and most precious gems.
Because of its density and weight, you can feel the difference between platinum and other precious metals when comparing different types of jewelry. Platinum is usually marked with the following symbols: PL, PT, PLAT, 950 or PT950. Since platinum is the purest metal, it rarely causes an allergic reaction. In the US and abroad, there is an increased interest in platinum jewelry, with wedding and engagement rings being the strongest selling category. The platinum group of metals (PGM), is comprised of six closely related metals: Platinum, Palladium, Rhodium, Ruthenium, Iridium and Osmium.
More info. on the P G M: Palladium, Rhodium, Ruthenium, Iridium Osmium.