Such alloys are used for jewelry, pen points, surgical pins and pivots, and electrical contacts and sparking points. Platinum-iridium alloys (5 to 10 percent iridium) are readily workable metals that are much harder and stiffer and more resistant to chemical attack than the soft pure platinum. Iridium is chiefly used in the form of platinum alloys. It can be dissolved in concentrated hydrochloric acid in the presence of sodium perchlorate at 125° to 150° C (257° to 302° F).īecause of difficulties in preparation and fabrication, the pure metal has few applications.
In the massive state the metal is practically insoluble in acids and is not attacked even by aqua regia. It is one of the densest terrestrial substances. A precious, silver-white metal, iridium is hard and brittle, but it becomes ductile and can be worked at a white heat, from 1,200° to 1,500° C (2,200° to 2,700° F). It is very dense and rare and is used in platinum alloys. Iridium (Ir), chemical element, one of the platinum metals of Groups 8–10 (VIIIb), Periods 5 and 6, of the periodic table. SpaceNext50 Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!.Learn about the major environmental problems facing our planet and what can be done about them! Saving Earth Britannica Presents Earth’s To-Do List for the 21st Century.Britannica Beyond We’ve created a new place where questions are at the center of learning.100 Women Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians.
IRIDIUM SILVER METALLIC HOW TO
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