In 1803 rhodium was discovered by William Hyde Wollaston in a South American piece of platinum ore.
He chose the name rhodium after the Greek rhodeos (rose red) because many compounds with rhodium showed this colouring. The new metal was subsequently used in 1820 as the tip of pens in a rhodium-tin alloy. Rhodium is one of the rarest non-radioactive metals in the earth's crust. It is found in Goodnews Bay in Alaska and in Stillwater, Montana. It is found in their ores together with platinum and gold, among others. Rhodium extraction, like the extraction of platinum metals in general, is extremely costly. Due to their great similarity, they are very difficult to extract from one another. In addition to the most important area of application, the production of catalysts, rhodium is also used in the jewellery industry to refine surfaces. Here, it takes on the task of tarnish protection, especially for silver and white gold alloys.