LYCOS RETRIEVER 
Iridium: Platinum
built 663 days ago
Iridium is a brittle and extremely hard metal. It is extremely inert chemically, resisting even the action of aqua regia. Iridium is used chiefly as an alloying material for platinum; the alloy, containing about 10 percent iridium, is much harder than pure platinum. Platinum-iridium alloys containing larger percentages of iridium are used in making precision instruments, needle points, surgical lasers and tools.
Source:
Iridium is the most corrosive resistant metal known. For this reason, the standard meter bar was created from an alloy of 90% platinum and 10% iridium. This bar was replaced as the definition of the meter in 1960 when the meter was redefined in terms of the orange-red spectral line of krypton-86.
Source:
Iridium is found uncombined in nature with platinum and other platinum group metals in alluvial deposits. Naturally occurring iridium alloys include osmiridium and iridiosmium, both of which are mixtures of iridium and osmium. It is recovered commercially as a by-product from nickel mining and processing.
Source:
Iridium, a metal of the platinum family, is white (similar to platinum) but with a slight yellowish cast. Because iridium is very hard and brittle, it is hard to machine, form, or work.
Source:
Iridium is a hard, brittle, lustrous, dense, transition metal of the platinum family. It is silvery-white and it is notable for being the most corrosion resistant element known. It is unaffected by air, water and acids.
Source:
Iridium is one of the transition metals, the elements that occur in the middle of the periodic table. It is ... classified as a member of the platinum group of metals, along with ruthenium, rhodium, palladium, osmium, and platinum.
Source:
MORE ABOUT
Platinum