irídium
Iridium is a chemical element with the symbol Ir and atomic number 77. It is a member of the platinum group metals and is extremely rare in the Earth's crust. Iridium is a very dense, silvery-white, hard, brittle, and highly corrosion-resistant metal. It is one of the densest naturally occurring elements, with a density of 22.56 g/cm³. Its melting point is 2466 °C (4471 °F) and its boiling point is 4428 °C (8002 °F).
Iridium is found in very small amounts in meteorites, and in trace amounts in some ores. It
These applications include the manufacture of spark plugs for high-performance engines, crucibles for high-temperature furnaces, and