The noble metals are most commonly considered to be ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold.
The platinum group consists of platinum, iridium, osmium, palladium, rhodium, and ruthenium.
Iridium radioisotopes are used in some radioisotope thermoelectric generators.
Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is the most widely traded.
The rhodium and iridium anions tend to be slightly unstable if the ligand is triphenylphosphine however, and quickly undergo reduction.
Additional graphite components provided impact protection, while iridium cladding of the fuel cells provided post-impact containment.
Iridium is used in particle physics for the production of antiprotons, a form of antimatter.
Iridium-192 is commonly used as a gamma ray source in industrial radiography to locate flaws in metal components.