Precious Metals | Rhodium jewelry

Rhodium Jewellery

Source: Canada, Russia (Ural Mountains), South Africa, USA

Rhodium is a rare, and highly reflective transition metal that is a member of the platinum group of metals, which appears as a chemical element on the periodic table, with the symbol (Rh) and an atomic number 45. Rhodium is used primarily as a hardening agent in the alloying of platinum and palladium. As a noble metal, rhodium is inert.

Rhodium is a naturally silvery-white metal that is sometimes used in jewelry making as an alloying agent or an electroplating treatment for white gold and can be used as a precious metal substitute for white gold and platinum. Rhodium is electroplated onto the surface of white gold to increase the reflectiveness. Rhodium has a lower density and weight than platinum, but it is heavier than gold. Due to its low electrical resistance, rhodium is also used as an electroplate finish on electrical contacts.

Rhodium's Discovery

In 1803, English chemist William Hyde Wollaston first identified the element rhodium and palladium, which he found within platinum ore from South America. Wollaston's extraction technique involved dissolving the platinum ore in a corrosive solution, to create palladium cyanide from which the pure palladium was extracted. The metal "rhodium" was named after the Greek work rhodon meaning "Rose." Up to 80 percent of the world's supply of rhodium comes from mines in South Africa.

Rhodium is a hard metal which has a hardness of 6.0 on the Mohs scale, with a Vickers Hardness (VHN or HV) of 1240. Rhodium has a melting point of around 1964º C.

Rhodium's Chemical Composition: (Rh)

Atomic Number: 45