Iridium
irid·i·um | i-ˈri-dē-əm
noun
A metal and member of the platinum family, which is often alloyed with platinum to improve workability
Iridium is a rare precious metal that is considered unique because it is both very hard and brittle compared to some other members of the platinum group of metals. To reduce its brittleness, it is often alloyed with platinum, with more platinum in a piece than iridium. Historically, Iridium is more commonly used in things like spacecraft, optical equipment, and medical equipment than in jewelry. It is, however, a beautiful metal and when used sparingly or in an alloy with platinum, it offers a striking silvery-white color for some types of jewelry. There are some pure-iridium jewelry pieces on the market as well, but they remain somewhat rare.