Rhodium is a rare silvery-white, hard, chemically inert transition metal. It is one of the six metals in the “platinum” group of noble or precious metals and one of the most valuable precious metals. Its most common use is as a catalyst in automotive catalytic converters. Because of its brilliant white color and reflectivity it is also commonly used for jewelry, making diamonds seem brighter and larger. Most “white gold” found today is actually a thin plate of rhodium over gold. Other industrial uses for rhodium include detectors in nuclear reactors, furnace windings, thermocouple elements, spark plug electrodes and laboratory crucibles.
Prodigy Surface Tech offers pure rhodium plate with no brighteners. Due to rhodium plate’s high internal stresses only thin deposits are possible.
MIL-R-46085: The MIL-R-46085 spec covers the requirements for the electrodeposition of rhodium over metallic surfaces.