Noun
A rare metallic element, of the same group as platinum, which it much resembles, being silver-white, but harder, and brittle, and indifferent to most corrosive agents. With the exception of osmium, it is the heaviest substance known, its specific gravity being 22.4. Symbol Ir. Atomic weight 192.5.
Source: Webster's dictionary191 Ir and 193 Ir are the only two naturally occurring isotopes of iridium, as well as the only stable isotopes ; the latter is the more abundant of the two. Source: Internet
About Iridium Communications Inc. Source: Internet
Another use concerns X-ray optics, especially X-ray telescopes. citation The mirrors of the Chandra X-ray Observatory are coated with a layer of iridium 60 nm thick. Source: Internet
He named iridium after Iris ( Ἶρις main), the Greek winged goddess of the rainbow and the messenger of the Olympian gods, because many of the salts he obtained were strongly colored. Source: Internet
Chemically, sulfur reacts with all elements except for gold, platinum, iridium, nitrogen, tellurium, iodine and the noble gases. Source: Internet
For example, the PGMs mined in South Africa contain on average 11% ruthenium while the PGMs mined in the former USSR contain only 2% (1992). citation citation Ruthenium, osmium, and iridium are considered the minor platinum group metals. Source: Internet