Gold, platinum, palladium and silver are generally used to create fine jewelry. From the time of their discovery until today, these materials were and still are considered precious metals. Stainless steel, tungsten and titanium are most often seen in men's jewelry. These are not materials used in fine jewelry.
Pure gold is too soft for everyday wear, so it is alloyed with other metals. Karatage, Marked with a K pertains the purity of the gold contained in a piece of jewelry. Gold Karat variations can be seen below.
The rarest of all precious metals, platinum is an extremely popular metal for jewelry. Although it is the most expensive It's most durable, resists tarnishing and is hypo-allergenic. Platinum is 95% pure with 5% alloy and should be marked with 950 Plat, PT950 or Plat. European jewelers, as well as some jewelers here in America, also use 90% pure or 900 platinum in Jewelry.
Palladium is a rare, permanent white metal with a high purity, similar to Platinum A hypoallergenic metal, palladium is 95% pure with 5% other pure alloys. Similar attributes to the Platinum metal, but lesser in cost. The weight of the Palladium metal is also lesser than Platinum. Look for "Pall 950", as the hallmark stamp of palladium.