It is a member of platinum group, silvery white, with symbol Pd, specific gravity of 12, lighter than platinum, stronger in ductility, slightly harder than platinum, and insoluble in organic acids, cold sulfuric acid or hydrochloric acid. But soluble in nitric acid and aqua regia. Under normal circumstances, it is not easy to oxidize and lose luster. Oxides will be produced on the surface around 400℃, but when the temperature rises to 900℃, the luster will be restored. At present, palladium is cheaper than platinum, and platinum is used alone in jewelry industry or as a component of gold, silver and platinum alloys. Ruthenium is sometimes added to increase its hardness. Common gold in the market, palladium's K gold and platinum-palladium alloy. Specifications are marked with Pd 1000, Pd950 and Pd900.

Platinum:

Also known as pure white gold, positive platinum or true platinum. But these names are unreasonable and easily confused with platinum. Its symbol is Pt, silvery white, its specific gravity is 2 1.35, its melting point is 1.700℃, its Mohs hardness is 4-4.5 degrees, its chemical properties are stable, and it is not corroded by acid and alkali except aqua regia.

Pure platinum is relatively soft, and the addition of metals such as ruthenium, rhodium and palladium will increase its hardness. South American Indians made platinum jewelry as early as15th century, and Europeans didn't adopt it until after the middle of19th century. At present, Japan is the largest consumer of platinum.

Platinum is the best.