by Trevin Hertzog
History of Iridium
Iridium was founded in France, England by a chemist named Smithson Tennant. He discovered this element in 1803, in the residue left when crude platinum had been dissolved in aqua regia (a mixture of hydrochloric acid and nitric acid). Tennant also discovered the element osmium at the same time.
It is found uncombined in nature in sediments that were deposited by rivers. It is commercially recovered as a by-product of nickel refining.
- Compass bearings
- Pen tips
- Standard meter bar
- Contacts in spark plugs
- Standard meter bar, which is an alloy of 90% Platinum and 10% Iridium
- Used in special alloys
- Forms an alloy with Osmium
Iridium is one of the rarest elements on earth, and can be found in a thin layer within the earth's crust.
Physical & Chemical Properties
Physical:Atomic Mass: 192.217 Atomic Radius (pm): 180pm Density: 22.650 g/cc
Melting Point: 2466 C (4471 F) Boiling Point: 4428 C (8002 F)
Appearance: Jagged/bumpy, weirdly shaped, & silver coloring
At room temp. (22 C): solid Hardness: Extremely hard Malleability: malleable
Conductivity: Conductor as solid, liquid not so good conductors
Unique property: highly colored salts & is one of the most corrosion- resistant metals
Flammability: Can be flammable when in finely derived dusts
Reactivity: Low reactivity (like gold), low toxicity, finely derived dusts are much more reactive