What type of metal is iridium
Iridarsenite is found with irarsite, ruthenarsenite and rutheniridosmine. It is found in nuggets and in fragments of natural Os-Ir-Ru alloys. The mineral is opaque with a high specific gravity of 10.9.Ĭhemistry and x-rays are necessary for conformation. It has a metallic lustre with hardness of 5-5.5. Its colour in polished section is medium grey with a brownish tint. Iridarsenite, (Ir,Ru)As2, is a monoclinic mineral that forms irregular inclusions. It is widespread and is reported from the following countries: Columbia, Canada, USA, Pap New Guinea, Indonesia, Australia, Russia, China, South Africa and in other minor occurrences. Main associates are platinum and various Pt-Fe alloys as inclusions. Its common occurrence is in placers derived from zoned ultramafic intrusions and from ophiolites. The specific gravity is extremely high at 22.6-22.8.Ĭhemistry, grand physical properties and environment aids in its identification. Possesses a high hardness of between 6 and 7. The mineral has a metallic lustre with a hackly fracture. It is opaque and silver-white colour with a yellow tinge. Twinning has been observed in polysynthetic groups. Iridium, Ir, can occur as cubic crystals and commonly as rounded or angular grains. The majority of the minerals containing the above elements are described below. Ruthenium uses are on the increase with such uses as in the manufacture of solar cells, in various chip resistors, chemical industry for anodes, catalysts, jewellery, corrosion resistant pipes and in eye tumour treatments. Canada and South Africa are the main producers with an annual production of around 12 tonnes.
Again most ruthenium is derived from by-product of nickel refining. Ruthenium is very rare with an average crustal abundance of about 1 part per billion. The metal has few uses but includes the following: various catalysts, staining organic tissues in electron microscopy preparations, some alloys and geological dating. About 100kg are used annually.Ĭanada is the leading producer along with Russia and South Africa. Again most of this element is derived from the by-product of nickel refining. Osmium possesses a crustal abundance of around 1 part per billion. The main uses are in the chemical, electrochemical industries, in crucibles, spark plugs, various alloys, in fountain pen nibs, compass bearings and in certain porcelains etc. Canada is the main producer along with South Africa and Russia. Most of this metal is extracted from the by-product of nickel refining. Iridium is one of least common metals with a crustal abundance of about 3 parts per trillion. Iridium metal is notably inert to reaction with acids, including aqua regia (a mixture of hydrochloric acid, HCl, and nitric acid, HNO 3, known for its ability to dissolve gold metal).Iridium, Ir, osmium, Os and ruthenium, Ru are among the rarest of the elements and thus they produce few minerals. In the case of fluorine, some 4 may also form.ĢIr(s) + 3Br 2(g) → 2IrBr 3(s) ĢIr(s) + 3I 2(g) → 2IrI 3(s) Reaction of iridium with acids
The trihalides iridium(III) fluoride, IrCl 3, iridium(III) chloride, IrCl 3, iridium(III) bromide, IrBr 3, and iridium(III) iodide, IrI 3, can be formed through the direct reaction of the metal with the halogen under anhydrous (dry) conditions. This material, with care, can be heated to form iridium(V) fluoride, which has the yellow tetrameric structure 4. Metallic iridium reacts directly with fluorine gas to form the highly corrosive iridium(VI) fluoride, IrF 6. Iridium does not react with water under normal conditions. If Ir 2O 3 is formed in the above reaction, it must oxidize further to IrO 2.
Usually second and third row d-block elements show similar chemistries, but in this case, rhodium (immediately above iridium in the periodic table) burns to give rhodium (III) oxide, Rh 2O 3. On heating with oxygen, iridium metal gives iridium (IV) oxide, IrO 2. Iridium is largely immune to atmospheric attack.