Palladium (pronounced /pəˈleɪdiəm/) is a chemical element with the chemical symbol Pd and an atomic number of 46. Palladium is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it after the asteroid Pallas, which in turn, was named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas.
Palladium, along with platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). Platinum group metals share similar chemical properties, but palladium has the lowest melting point and is the least dense of these precious metals.
The unique properties of palladium and other platinum group metals account for their widespread use. One in four goods manufactured today either contain platinum group metals or had platinum group metals play a key role during their manufacturing process. Over half of the supply of palladium and its congener platinum goes into catalytic converters, which convert up to 90% of harmful gases from auto exhaust (hydrocarbons, carbon monoxide and nitrogen oxide) into less harmful substances (nitrogen, carbon dioxide and water vapor). Palladium is found in many electronics including computers, mobile phones, multi-layer ceramic capacitors, component plating, low voltage electrical contacts, and SED/OLED/LCD televisions. Palladium is also used in dentistry, medicine, hydrogen purification, chemical applications, and groundwater treatment. Palladium plays a key role in the technology used for fuel cells, which combines hydrogen and oxygen to produce electricity, heat and water.
Palladium bullion has ISO currency codes of XPD and 964. Palladium is one of only four metals to have such codes, the others being gold, silver and platinum.
Ore deposits of palladium and other platinum group metals are rare, and the most extensive deposits have been found in the norite belt of the Bushveld Igneous Complex in the Transvaal in South Africa, the Stillwater Complex in Montana, United States, the Sudbury District of Ontario, Canada, and the Norilsk Complex in Russia. In addition to mining, recycling is also a source of palladium, mostly from scrapped catalytic converters. The numerous applications and limited supply sources of palladium result in palladium drawing considerable investment interest.