Palladium is a lustrous silvery white metal with the atomic number 46 and chemical abbreviation of Pd. It is used in electronics, jewelry, and certain other industries. Because the metal is extremely rare, palladium is considered to be a precious metal, and it can command a high price on the open market. Consumers are probably most familiar with it in the form of alloys with other metals, or inclusion within electronics. When electronics are recycled and stripped down, palladium is one of the metals that is frequently removed so that it can be reused.
The metal was discovered in 1803 by William Hyde Wollaston, who named it palladium after the asteroid Pallas. The asteroid, in turn, was named for a Greek Goddess of Wisdom. The metal often occurs in conjunction with platinum, and it is frequently associated with gold, nickel, and copper. It resists tarnish, and is extremely ductile, meaning that it takes readily to working. When palladium is cold worked, the tensile strength greatly increases.
Alloys with palladium are used to make electronic components, especially contacts. It is also used in the manufacture of surgical instruments, and in some jewelry, especially in the production of white gold, which is an alloy of gold with a white metal. The metal is also sometimes used in purification and processing, and it is able to absorb up to 900 times its volume in hydrogen. This property is often harnessed in scientific experiments.
As a member of the platinum group, which also includes metals like rhodium and iridium, palladium is considered a transition metal. It is one of the softer metals in the platinum group, but it retains other valuable properties that are shared by metals in this group. In addition to being tarnish resistant, palladium resists chemical erosion as well as intense heat, and it is highly electrically stable. Many of these metals are used as catalysts because of these well established physical and chemical properties.
While palladium is not the most expensive precious metal, it can be quite costly. On occasion, the market will be scarce, since manufacturers sometimes stockpile it to avoid shortages on important products. The metal is available both in a pure and alloyed form from various supply companies. Special metalworking techniques are required to work with palladium, which can become brittle or discolored if it is not handled properly. Pure palladium jewelry is available through high-end retailers.