The platinum group metals (PGM), comprise six closely related metals: Platinum, Palladium, Rhodium, Ruthenium, Iridium and Osmium.
Platinum has a deep luster and a rich, white color. It is rarer, heavier and denser 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 because it holds gemstones most securely and it neutral color enhances the brilliance and depth of diamonds and precious stones.
In the United States platinum is usually marked: PT or PLAT
In Europe, it is marked: 950 or PT950
Platinum Group Metals (PGM):
It is a relatively rare and soft, silvery white metal. When used in jewelry, it is alloyed with gold to create white gold. It is also used to make setting.
It is a brilliant silvery white metal that is used as a plating agent on platinum and white gold to create a white very hard coating.
It is a grayish-white metal that has a high resistance to wear and is used in the manufacture of jewelry, porcelain, etc.
It is a 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.
It is a bluish-white, brittle metal. Osmium and platinum alloy is used for standard weights and measures.