Rhodium is an element that has industrial uses and is also used for plating jewelry made of other metals. It is quite rare, with production being only about 3 tons a year. Although dangers are involved with industrial uses, there do not seem to be health issues when rhodium is used in jewelry.
Identification
Rhodium is a white metal. It is the rarest of the nonradioactive metals found on earth, and is considered the most expensive metal. Its symbol on the periodic table is Rh, and its atomic number is 45. Rhodium is a member of the platinum group, which also includes platinum, palladium, ruthenium, iridium and osmium. Rhodium is extremely resistant to corrosion; does not tarnish; and is durable, hard and reflective. Because of its rarity, rhodium has no effect on the environment.
Rhodium is used for plating jewelry. The metallic element is commonly used to plate white gold and platinum, where it increases durability, prevents scratching and improves brightness. Rhodium is hypoallergenic and is often used as a protective coating for white gold, which may contain nickel. About 15 percent of the population is allergic to nickel, so rhodium prevents skin irritation. Rhodium is not malleable and would break in its pure form, so you will not find pure rhodium jewelry. Rhodium can be used to plate less expensive metals, like sterling silver or brass. Once the rhodium is applied, the jewelry will look the same, no matter what metal is underneath.
Rhodium Dangers

The process of plating the jewelry with rhodium requires rhodium to be a powder, so the jewelry maker must use care. Plating can wear off in time, depending on use, so your skin could be exposed to the metal underneath the rhodium. The rhodium itself, used as plating or occasionally mixed with other metals to form jewelry, has no documented danger to the wearer of the jewelry.