Sinonimi: Ir | atomic number 77
ETYM New Lat., from Latin iris, iridis, the rainbow. So called from the iridescence of some of its solutions. Related to Iris.
Rare, hard, platinumlike metal.
A heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium; SYN. Ir, atomic number 77.
Hard, brittle, silver-white, metallic element, symbol Ir, atomic number 77, atomic weight 192.2. It is twice as heavy as lead and is resistant to tarnish and corrosion. It is one of the so-called platinum group of metals; it occurs in platinum ores and as a free metal (native metal) with osmium in osmiridium, a natural alloy that includes platinum, ruthenium, and rhodium.
It is alloyed with platinum for jewelry and used for watch bearings and in scientific instruments. It was named in 1804 by English chemist Smithson Tennant (1761–1815) for its iridescence in solution.