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What is Iridium?

A hypodermic syringe made with iridium.
Iridium has the atomic number of 77, and the symbol Ir on the periodic table of elements,.
Iridium may be found in gravel deposits.
Iridium is named for Iris, the goddess of rainbows.
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  • Written By: Mary Elizabeth
  • Edited By: Bronwyn Harris
  • Last Modified Date: 09 December 2014
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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 was also he discoverer of osmium.

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.

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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.

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.

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Discuss this Article

anon166098
Post 9

where is iridium available? Santhosh

anon140611
Post 6

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

anon78126
Post 5

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
Post 3

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
Post 2

can you tell me how to test this material?

srifi
Post 1

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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