A very hard and brittle, exceptionally corrosion-resistant, whitish-yellow metallic element occurring in platinum ores and used principally to harden platinum and in high-temperature materials, electrical contacts, and wear-resistant bearings. Atomic number 77; atomic weight 192.2; melting point 2,410°C; boiling point 4,130°C; specific gravity 22.42 (at 17°C); valence 3, 4. See Table at element.
A metallic substance element (symbolization Ir) with an atomic amount of 77.
an unusual metallic element of atomic quantity 77, of the same group as platinum, which it much resembles, being silver-white and indifferent to most corrosive representatives, but harder, much more brittle, along with a higher melting temperature (2410° C, versus platinum 1772° C). With the exception of osmium, it will be the heaviest compound understood, its specific-gravity being 22.4. Representation Ir. Atomic fat 192.22.
Chemical image, Ir; atomic body weight, 193. A metal of silver-white shade, from the platinum household, and, as far as understood, constantly contained in native platinum.
a heavy brittle metallic part of the platinum team; used in alloys; does occur in all-natural alloys with platinum or osmium