Many medical and surgical advances, such as pacemakers, have also relied upon iridium's unique qualities. In 1889, in Paris, a platinum-iridium alloy bar was cast as the standard unit length of the metre and remained as the definition for this distance until 1960 when more precise measurement methods replaced it. Iridium first found a use in the nibs of fountain pens, due to its extreme hardness. It is still produced today from platinum ore and as a by-product of nickel mining. Obtaining pure samples of iridium remained impossible, however, due to its high melting point, until 1842 when an American chemist called Hare used a hydrogen/oxygen flame to melt a small sample, allowing it to be separated from dross and other impurities. Collet-Descotiles upon whose research Tennant also acted. Much of the credit for the discovery should also go to Frenchmen L.N. In 1804, Tennant isolated iridium (and osmium) from the residues and, due to its colourful compounds, named it after the Latin for rainbow, "iridis". Having discovered platinum and palladium, William Hyde Wollaston handed over the remaining residues of ore to his commercial partner Smithson Tennant, a fellow Cambridge graduate with whom he had forged a partnership in 1800. Tensile strength 112 (annealed condition kg/mm2) History PropertiesĮlectrical conductivity* 0.197 106 cm-1 Ohm-1Ĭhemical element of Group VIII (Mendeleev) It also has industrial applications such as the production of chlorine and caustic soda. Iridium can be found in health technology combating cancer, Parkinson's disease, heart conditions and even deafness and blindness.Ī shiny, oxidation-resistant metal, iridium also adds to the brilliance and durability of jewellery. Its biological compatibility is what we owe most to iridium as this enables it to be used in a range of medical and surgical applications. It is white with a yellowish hue.Īlthough brittle, it is extremely hard (over four times that of platinum itself) and with its high melting point, temperature stability and corrosion resistance, is used in high-temperature equipment such as the crucibles used to grow crystals for laser technology. Send us feedback.The rarest of the PGMs, iridium is second only to osmium as the densest element and is the most corrosion resistant known. These example sentences are selected automatically from various online news sources to reflect current usage of the word 'iridium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. 2021 The Census Bureau’s count for other precious metals includes silver, platinum, palladium and more obscure sources such as ruthenium and iridium.ĭian Zhang, USA TODAY, 3 Mar. 2021 The core helped to precisely date the sediments containing iridium-rich dust.ĭavid Bressan, Forbes, 24 Feb. 2021 In addition, the surfaces of the pottery and meltglass are speckled with tiny melted metallic grains, including iridium with a melting point of 4,435 F (2,466 C), platinum that melts at 3,215 F (1,768 C) and zirconium silicate at 2,800 F (1,540 C).Ĭhristopher R. 2021 Here’s the research setup: A woman speaks Dutch into a microphone, while 11 tiny needles made of platinum and iridium record her brain waves.Īdam Rogers, Wired, 9 Nov. 2022 In addition to iridium, the crater section showed elevated levels of other elements associated with asteroid material.ĭavid Bressan, Forbes, 24 Feb. 2022 What's more, the fish were found just beneath a layer of rock known as the iridium anomaly, which is rich in a dense element common in asteroids and rare on Earth. Sarah Scoles, Scientific American, 11 Mar. 2021 In Colorado, for instance, 27 buildings house scary-sounding elements such as cesium 137, cobalt 60, americium 241 and iridium 192. A host of melted elements and minerals, such as platinum, iridium, and quartz.Įlizabeth Fernandez, Forbes, 23 Sep. Recent Examples on the Web Melted pottery shards, which melt at temperatures above 1500C.
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