Use of Rhodium

Rhodium is a so-called noble metal, resistant to corrosion, found in platinum- or nickel ores together with the other members of the platinum group metals. The element's major use (about 80% of world rhodium production) is as one of the catalysts in the three-way catalytic converters of automobiles.

Rhodium is used as an alloying agent for hardening and improving the corrosion resistance of platinum and palladium. These alloys are used in furnace windings, bushings for glass fiber production, thermocouple elements, electrodes for aircraft spark plugs, and laboratory crucibles. Other uses include:
An electrical contact material due to its low electrical resistance, low and stable contact resistance, and high corrosion resistance.
Plated rhodium, made by electroplating or evaporation, is extremely hard and is used for optical instruments.
It is also used as a filter in mammography systems because of the characteristic X-rays it produces.[