The platinum group metals (PGM), comprise six closely related metals: Platinum, Palladium, Rhodium, Ruthenium, Iridium and Osmium.
Platinum ( simbol Pl) was excepted as a precious metal only after second half of 19th century and has a deep luster and a rich, white color. It is rarer and heavier than all precious metals and considered to be more valuable than gold.
Platinum is often used to set the most valuable gems to produce the finest jewelry. Platinum holds gemstones most securely, because its strength and neutral color enhances the brilliance and depth of diamonds and precious stones. Because of its density and weight, you can feel the difference between platinum and other precious metals. There are no karat marks to identify platinum. In the United States platinum is usually marked: PT or PLAT. In Europe, platinum is identified by the following marks: 950 or PT950.
Since platinum is the purest metal it rarely causes an allergic reaction. There is an increased interest in platinum jewelry both in the US and abroad. Bridal rings being the strongest selling category.
The Platinum Group Metals (PGM) commonly occur together in nature and are among the scarcest of the metallic elements. Along with gold and silver, they are known as precious or noble metals. They occur as native alloys in placer deposits or, more commonly, in lode deposits associated with nickel and copper. Nearly all of the world's supply of these metals are extracted from lode deposits in four countries--the Republic of South Africa, the U.S.S.R., Canada, and the United States. The Republic of South Africa is the only country that produces all six PGM in substantial quantities.
The Platinum group metals (PGM) comprise six closely related metals:
Palladium Palladium (symbol Pd), relatively rare, silvery white and relatively soft metal. Was discovered in 1804 by the British chemist William Hyde. Palladium used in jewelry, alloyed with gold, in what is called white gold.
Rhodium Rhodium, brilliant silvery white metal (symbol Rh) derives its name from Greek rhodon -rose , was discovered in 1803 by the British chemist William Hyde Wollaston. Pure rhodium is used as a plating finish for jewelry and silverware.
Ruthenium Ruthenium (symbol Ru), chemically unreactive, grayish-white metal. Was discovered in 1844 by the Russian chemist Karl Klaus. Ruthenium and platinum alloys have a high resistance to wear and are used in the manufacture of jewelry, porcelain, etc.
Iridium Iridium (symbol Ir), white, brittle and extremely hard metal. The alloy, which contains about 10 percent iridium and 90% platinum, is much harder than pure platinum. Alloys containing larger percentages of iridium are used in making precision and standard instruments, surgical tools, pen points.
Osmium Osmium (symbol Os) bluish-white, brittle metal. Along with iridium, osmium is generally considered the most dense element. Was discovered in 1803 by the British chemist Smithson Tennant. Osmium and platinum alloy is used for standard weights and measures.