Iridium

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/cm3 (0.815 lb/cu in) as defined by experimental X-ray crystallography.

Platinum-iridium alloys (5 to 10 percent iridium) are readily workable metals that are much harder and stiffer and more resistant to chemical attack than the soft pure platinum. Such alloys are used for jewelry, pen points, surgical pins and pivots, and electrical contacts and sparking points.

Hydrogen

Identity.

Iridium is a chemical element with the symbol Ir and atomic number 77. It belongs to the group of transition metals and is part of the platinum group elements. Known for its extreme hardness, high melting point, and exceptional corrosion resistance, iridium finds applications in various industrial and scientific fields.

History.

Iridium's story begins alongside its platinum group neighbor. In 1803, English chemist Smithson Tennant dissolved platinum ore in a powerful acid mixture. The resulting black residue revealed not one, but two new elements. Tennant named the rainbow-colored compounds formed by one element iridium, inspired by the Greek word "iris."

Despite initial challenges in isolating and working with iridium, its unique properties, including its exceptional hardness and high melting point, have garnered scientific and industrial interest.

Paracelsus

Usage.

  • Extreme hardness and wear resistance: This makes it ideal for tipped pen nibs and surgical instruments that need to maintain their sharpness over time.
  • High melting point and heat resistance: This allows iridium to be used in spark plugs and high-temperature crucibles for scientific research.
  • Surgical instruments: Employed in specific instruments requiring exceptional hardness and sharpness.
Some of the benefits of using iridium are:
Iridium is a durable and tough metal, providing a long service life and high performance under extreme conditions. A lower voltage is required to create a spark, leading to greater fuel economy. Excellent heat resistance up to 2400°C. Superior corrosion resistance.

Sources.

Iridium generally is produced commercially along with the other platinum metals as a by-product of nickel or copper production. Iridium-containing ores are found in South Africa and Alaska, U.S., as well as in Myanmar (Burma), Brazil, Russia, and Australia.