Platinum (Pt): Platinum is probably the most recognized of the PGMs because of its use in jewelry, but its main application is the manufacture of catalytic converters as well as other industrial applications. Platinum has a high melting point and temperature stability, is highly corrosion oxidation resistant, and it is a good oxidation catalyst. Platinum is biologically compatible and has many significant applications in medicine.

Palladium (Pd): Palladium is also used to make jewelry although it’s not as popular as platinum. Palladium’s unique quality is its ability to absorb hydrogen, which has applications in chemical processes that require hydrogen exchange between two reactants, such as that which produces the raw materials for synthetic rubber and nylon. Palladium is chemically stable and like platinum has excellent catalytic properties so it can be used as a substitute for the more expensive platinum in catalytic converters.

Rhodium (Rh): Rhodium, another highly-active catalyst, is widely used in vehicle emission control systems. Rhodium is also used to make glass thanks to its high melting point and temperature stability.

Iridium (Ir): Iridium is the rarest and most corrosion resistant of the PGMs. It is very dense and has a high chemical and thermal stability. Like platinum, iridium is biologically compatible and has many medical applications.

Ruthenium (Ru): Although brittle, ruthenium is very hard and is a good alloying agent for platinum and palladium. Like the other PGMs, it has a high melting point and superior catalytic properties. Ruthenium is used in the electrical and electrochemical industries for its conductive properties and durability.

Osmium (Os): As the densest and hardest of the group, osmium is often alloyed with other PGMs such as platinum and iridium. Osmium also is an excellent conductor of electricity and an effective oxidation catalyst.  Common applications for osmium include fuel cells and forensic science.