Its price or scarcity may be the reason for its now omission from pen nibs. Over time ruthenium, rhodium, osmium metals have now replaced it in pen nibs and has been labeled as "Genius Iridium". Historically, iridium was used a a tip material for fountain pen nibs and seen as a product of quality. This switch has many benefits such as requiring a lowering the amount of water and reducing the number of drying agents in the process. Ruthenium promoted iridium catalysts are superior to the rhodium-based system (Monsanto process). Originally using a rhodium-containing catalyst, an iridium-containing catalyst has replaced rhodium for the production of acetic acid as part of the Cativa process. It is also used in many objects such as in crucibles and other applications that require high temperatures, in electrical contacts, as a hardening agent for platinum, as a nib for fountain pens, and even jewelry. Because of its higher melting temperature, compared to palladium and gold, these plugs can provide a better performance than other plugs except for some ruthenium alloys. Its use in spark plugs that is anti-corrosive and heat-resistant providing longer lasting and seemingly care-free plugs. ApplicationsĮven though being one of the rarest elements in the earth, iridium does provide a good degree of functionality serving many purposes. It is also a by-product of the nickel mining process. Each is a different mixture of osmium and iridium. It occurs in nature uncombined, combined with platinum, or found in the natural alloys of osmiridium and iridosmine. Most acids do not cause damage due to its high corrosion-resistance. Its high hardness, brittleness, and high melting point (approximately 2500 degrees Celsius) make the metal difficult to work with or form. It has a silvery-white color resembling platinum and palladium. Iridium is part of the platinum group metals (PGMs). The name was chosen as Iris, personification of a rainbow, due to the diverse colors of its salts. Even though Tennant is credited with its discovery, a few French chemists had also claimed credit to discovery the element. It was found in the residue of platinum ores.
Iridium was discovered in 1803 by Smithson Tennant. This was done by comparing the high metal occurrence found near the craters with chondritic meteorites and asteroids, which have a higher concentration than in the earth's crust. Being one of the rarest elements in the crust of the earth, iridium has been used to show a link between dinosaur extinction and impact craters. It was discovered by scientist Smithson Tennant in 1803 and named after the Greek goddess Iris. It is the second densest metal next to Osmium. Its chemical symbol is Ir with an atomic number of 77. Iridium is a transition metal from the platinum group. Iridium is a platinum group metal and is one of the rarest metals on Earth.