Element Iridium, Ir, Transition Metal

In 1803 Wollaston found palladium in crude platinum by dissolving it in aqua regia. Simultaneously Victor Collet-Descotils, Antoine Francois de Fourcroy and Nicolas Louis Vauquelin took over the research of the residue formed by the platinum dissolution in aqua regia. They fused it with potash, extracted the cooled melt with water to give a solution in which they believed new, still unidentified, metals were contained. Using the same method of of dissolving crude platinum in aqua regia Tennant isolated in 1804 two new metals, osmium and iridium. The element was named after the Greek word for rainbow because of many of its salts (chlorides) striking variety of strong colours.

Transition Metal Iridium crustal abundance is 1x10^-7% mass %. The main minerals are nevyanskite (osmiridium, iridium + osmium), syssertskite, platinum, rhodium and ruthenium nevyanskite and aurosmirid. Beside osmium and iridium they contain also several other mineral forming elements and belong to the solid solutions class. Traced amounts (~ 10^-4%) of Iridium also occur in various sulphide copper-nickel iron-bearing ores.