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Iridium is a chemical element; it has symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group , it is considered the second-densest naturally occurring metal (after osmium ) with a density of 22.56 g/cm 3 (0.815 lb/cu in) as defined by experimental X-ray crystallography .
The type locality of this iridium anomaly is near Raton, New Mexico. [1] [2]Iridium is a very rare element in the Earth's crust, but is found in anomalously high concentrations (around 100 times greater than normal) in a thin worldwide layer of clay marking the boundary between the Cretaceous and Paleogene periods, 66 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.
The Iridium system was designed to be accessed by small handheld phones, the size of a cell phone. While "the weight of a typical cell phone in the early 1990s was 10.5 ounces" [6] (300 grams) Advertising Age wrote in mid 1999 that "when its phone debuted, weighing 1 pound (453 grams) and costing $3,000, it was viewed as both unwieldly and expensive."
Iridium Communications Inc. (formerly Iridium Satellite LLC) is a publicly traded American company headquartered in McLean, Virginia, United States.Iridium operates the Iridium satellite constellation, a system of 80 satellites: 66 are active satellites and the remaining fourteen function as in-orbit spares. [2]
This category has the following 2 subcategories, out of 2 total. I. Iridium minerals (4 P) O. Organoiridium compounds (11 P) Pages in category "Iridium compounds"
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They have similar physical and chemical properties, and tend to occur together in the same mineral deposits. [2] However, they can be further subdivided into the iridium-group platinum-group elements (IPGEs: Os, Ir, Ru) and the palladium-group platinum-group elements (PPGEs: Rh, Pt, Pd) based on their behaviour in geological systems.