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What is Iridium?

Mary Elizabeth
Mary Elizabeth
Mary Elizabeth
Mary Elizabeth

Iridium is a metallic element with the atomic number 77 and the symbol Ir. On the periodic table of elements, it is found in Group 9, between platinum and osmium. It is referred to as a “transition metal” and also as a “platinum metal,” along with ruthenium, rhodium, palladium, osmium, and platinum itself.

Iridium is a metallic element that is both hard and brittle. Described as whitish-yellow or silvery in color, it just a little less dense than osmium, which is the densest element—22.560 gm/cm3 compared to 22.6 gm/cm3 .

Iridium was discovered by Smithson Tennant, an English chemist, in London, England in 1803, and it’s name comes from the Latin for iris, the goddess of the rainbow on account of its colored salts. Tennant also discovered osmium.

A hypodermic syringe made with iridium.
A hypodermic syringe made with iridium.

It is found in gravel deposits, and believed to occur only in alloys with other noble metals, i.e., not in an uncombined state. Often it is found alloyed with osmium in compounds called osmiridium and iridiosmium, the origin of the names being obvious. It is, however, extremely scarce, occurring in only .001 ppm in the Earth’s crust.

Iridium has a number of uses. It is used to harden platinum, combined with osmium in creating gold-tip pens, and to make highly specialized crucibles. It iridium can be involved in cancer irradiation, as well as the making of hypodermic syringes and surgical pins. Other uses include spark plugs for helicopters, pivot bearings, and extrusion dies.

Iridium has the atomic number of 77, and the symbol Ir on the periodic table of elements,.
Iridium has the atomic number of 77, and the symbol Ir on the periodic table of elements,.

One very special use of iridium is its role in the weights and measures standard for the kilogram, which is made of an alloy of iridium (10%) and platinum (90%). On account of exceptionally high amounts of iridium in rocks dating to between the Cretaceous period and the Tertiary period, t is speculated by some that iridium was a component of an asteroid that struck the Earth and led to the extinction of the dinosaurs.

Mary Elizabeth
Mary Elizabeth

Mary Elizabeth is passionate about reading, writing, and research, and has a penchant for correcting misinformation on the Internet. In addition to contributing articles to AllTheScience about art, literature, and music, Mary Elizabeth is a teacher, composer, and author. She has a B.A. from the University of Chicago’s writing program and an M.A. from the University of Vermont, and she has written books, study guides, and teacher materials on language and literature, as well as music composition content for Sibelius Software.

Learn more...
Mary Elizabeth
Mary Elizabeth

Mary Elizabeth is passionate about reading, writing, and research, and has a penchant for correcting misinformation on the Internet. In addition to contributing articles to AllTheScience about art, literature, and music, Mary Elizabeth is a teacher, composer, and author. She has a B.A. from the University of Chicago’s writing program and an M.A. from the University of Vermont, and she has written books, study guides, and teacher materials on language and literature, as well as music composition content for Sibelius Software.

Learn more...

Discussion Comments

anon166098

where is iridium available? Santhosh

anon140611

can you please let us know how to test a copper-iridium mixture?

anon78126

Nowadays, the mixing of this alloy in gold cannot be traced/identified by any person. Due to mixing of this metal in gold ornaments people are fearful of radiation which increases the chance of cancer.

saif

One person is telling me that he has iridium but it's a vessel shape. but i don't know how to test the material. can you just tell me how to test the material? who will buy that kind of material and what could be the cost for that? thank you. SAIF

anon44261

can you tell me how to test this material?

srifi

One of my friends was talking about iridium copper is it true? if yes can i talk to him.What are the procedures to test it please answer to my query & send mail

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    • A hypodermic syringe made with iridium.
      By: Swapan
      A hypodermic syringe made with iridium.
    • Iridium has the atomic number of 77, and the symbol Ir on the periodic table of elements,.
      By: jelena zaric
      Iridium has the atomic number of 77, and the symbol Ir on the periodic table of elements,.
    • Iridium is named for Iris, the goddess of rainbows.
      By: Dmitry Pichugin
      Iridium is named for Iris, the goddess of rainbows.
    • Iridium may be found in gravel deposits.
      By: nito
      Iridium may be found in gravel deposits.
    • Iridium was discovered by a London chemist in 1803.
      By: Helen Hotson
      Iridium was discovered by a London chemist in 1803.
    • Iridium may be used in the creation of spark plugs for helicopters.
      Iridium may be used in the creation of spark plugs for helicopters.