Iridium

Iridium, a rare, white metallic element, appearing 77th on the Periodic Table, shares some characteristics as the other elements, however being unique as it is, offers far more than a rare and metallic appearance. It also bares the concept of being one of the hardest metals, extremely dense metals, and its outstanding resistance against corrosion: better than any other metal known. In most cases, Iridium occurs in gravel deposits with a related element called platinum. Iridium occurs naturally in the metallic state in an alloy with platinum called platiniridium, which contains palladium, copper, and iron as contaminants. Separation of the platinum from the Iridium is a complex process, involving many techniques. Ores and deposits containing the free metal are rare. Those that do exist are found primarily in the Ural Mountains of the Russian Federation, in Alaska, Ontario, North America, South Africa, and in Tasmania. Iridium, however, being too brittle to be used by it! self, is often mixed with platinum as a hardening agent. Such products as containers for heating chemicals, as well as other high temperature or corrosive usable containers are made from Platinum-Iridium alloys. Manufacturers also use these and other Iridium alloys for making jewelry, fountain pen tips, and bearings for navigational compasses. Other uses of the metal come under different forms, such as radioactive Iridium, which can be used as a source of gamma rays. Also, the element is used extensively in commercial electrical contacts. Iridium has the atomic symbol Ir. Its atomic number, as stated above is 77 and its atomic weight is 192.22. It melts at 2410 C and boils at 4130 C. It has a density of 22.65 grams per cubic centimeter at 20 C. Metallic Iridium has a face-centered cubic crystalline structure. Iridium belongs to the group of metals called transition metals. Its name is derived from the Greek goddess Iris, goddess of the rai...