After the discovery of platinum and palladium, the search for another platinum metal yielded, in 1803, the discovery of rhodium, named because of its distinctive red-to-rosy coloured salts.

Rhodium is a platinum metal and shares some of the notable properties of platinum, including its resistance to corrosion, its hardness and ductility. Wherever there is platinum in the earth, there is rhodium as well. In fact, most rhodium is extracted from a sludge that remains after platinum is removed from the ore. A high percentage of rhodium is also found in certain nickel deposits in Canada.

Rhodium has a very high melting point and good electrical conductivity. These properties make it suitable for high temperature alloys, electrical devices, and furnace windings. Other uses include its use in the manufacture of special high temperature crucibles for laboratory applications. It is also a good hardener for platinum and palladium. Rhodium also makes a lustrous, hard coating for other metals in such items as table silver and camera parts. A thin film of rhodium deposited on glass makes excellent mirrors.

BCIT Chemistry Resource Center
http://nobel.scas.bcit.ca/resource/