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Iridium is one of the characteristic elements of extraterrestrial rocks, and, along with osmium, can be used as a tracer element for meteoritic material in sediment. [ 71 ] [ 72 ] For example, core samples from the Pacific Ocean with elevated iridium levels suggested the Eltanin impact of about 2.5 million years ago.
Iridium compounds are compounds containing the element iridium (Ir). Iridium forms compounds in oxidation states between −3 and +9, but the most common oxidation states are +1, +2, +3, and +4. [2] Well-characterized compounds containing iridium in the +6 oxidation state include IrF 6 and the oxides Sr 2 MgIrO 6 and Sr 2 CaIrO 6.
Organoiridium compounds share many characteristics with those of rhodium, but less so with cobalt. Iridium can exist in oxidation states of -III to +V, but iridium(I) and iridium(III) are the more common. iridium(I) compounds (d 8 configuration) usually occur with square planar or trigonal bipyramidal geometries, whereas iridium(III) compounds (d 6 configuration) typically have an octahedral ...
The platinum-group metals (PGMs), also known as the platinoids, platinides, platidises, platinum group, platinum metals, platinum family or platinum-group elements (PGEs), are six noble, precious metallic elements clustered together in the periodic table. These elements are all transition metals in the d-block (groups 8, 9, and 10, periods 5 ...
Gold nugget A selection of precious metal elements; gold, silver, platinum, palladium, copper, ruthenium, rhodium, rhenium, osmium, iridium and mercury. They are labeled and arranged by their location on the periodic table. Precious metals are rare, naturally occurring metallic chemical elements of high economic value.
In more specialized fields of study and applications the number of elements counted as noble metals can be smaller or larger. It is sometimes used for the three metals copper, silver, and gold which have filled d-bands, while it is often used mainly for silver and gold when discussing surface-enhanced Raman spectroscopy involving metal ...
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Most definitions of the term 'refractory metals' list the extraordinarily high melting point as a key requirement for inclusion. By one definition, a melting point above 4,000 °F (2,200 °C) is necessary to qualify, which includes iridium, osmium, niobium, molybdenum, tantalum, tungsten, rhenium, rhodium, ruthenium and hafnium. [2]