Metallic element of the platinum group of metals boiling point 3727 degrees C and melting point of 1966 degrees C. Discovered in 1804 by the British chemist William Hyde Wollaston. Rhodium metal occurs as an alloy in platinum ores, in osmiridium, and in gold rhodium ores called rhodite. Of the elements in the crust of the earth, it ranks fifty-ninth in abundance. The metal is a brilliant silvery white and is hard and durable. It is insoluble in ordinary acids and is very difficult to fuse. It has a hardness of 4. Rhodium is used usually as an alloy with platinum; the resulting alloy has the desirable properties of platinum and is also hard and durable. It is sometimes used as a plating finish for jewelry and silverware.