Rhodium (Greek "rhodon" (ῥόδον) meaning "rose") was discovered in 1803 by William Hyde Wollaston, soon after his discovery of palladium. He used crude platinum ore presumably obtained from South America. His procedure involved dissolving the ore in aqua regia and neutralizing the acid with sodium hydroxide (NaOH). He then precipitated the platinum as ammonium chloroplatinate by adding ammonium chloride (). Most other metals like copper, lead, palladium and rhodium were precipitated with zinc. Diluted nitric acid dissolved all but palladium and rhodium. Of these, palladium dissolved in aqua regia but rhodium did not, and the rhodium was precipitated by the addition of sodium chloride as . After being washed with ethanol, the rose-red precipitate was reacted with zinc, which displaced the rhodium in the ionic compound and thereby released the rhodium as free metal.