Product Reference

Physical and chemical characteristics:

• Latin name Iridium (Ir);
• chemical element of Group VIII in Mendeleev's periodic table;
• Atomic number 77;
• Atomic weight 192.22, a platinum group metal;
• Density 22.65 g/cmі;
• Melting point 2,447°C.

History:

Iridium is a platinum group metal. In 1804, the British chemist, Smithson Tennant, examined a black powder which was left after dissolving virgin platinum in aqua regia, and found that it contained two new elements. The salts of one of these new elements were coloured, quite literally, with all the colours of the rainbow. Tennant did not think too long about what to call his discovery, choosing the name "iridium", from the Greek "iris", or "rainbow".

The world is not rich in this metal, with reserves in the ground not exceeding millionths of a per cent of the earth's geological make-up. Each year, not more than a single ton of this metal is produced world-wide.

Uses:

Iridium is used for protective coverings, and is a component of alloys with Pt, Os and others that are used in the manufacture of chemical apparatus, weights and measures, parts for measuring equipment and the soldering in fountain pens. The addition of very small quantities of iridium to tungsten and molybdenum helps them maintain their strength at high temperatures. This metal is used to make crucibles for laboratory use, specifically for conducting experiments involving fluorine and its volatile compounds. Iridium is also used for making glass-blowing mouthpieces. A thermocouple with electrodes made from iridium and an iridium-mercury or iridium-rhodium alloy has been constructed for measuring temperatures of between 2,000° and 2,300°C.