Brief Description:
Iridium is another dense metal, mostly white in appearence save for a slight yellowish tinge. It is extremely hard and brittle, and is the most corrosive-resistant metal known to man. An iron-loving element, most of the earth's iridium is found in its iron core. However, asteroids and other extraterrestrial debris contain high concentrations of iridium; a layer with high iridium content at the end of the Cretaceous period points to a meteor or comet impact as the killer of the dinosaurs.