Hallmarks are distinguishing characteristics that are stamped on gold, silver and platinum items - typically to identify the items purity. There are also hallmarks that can identify where the item was made (called a makers mark), the office the metal was tested in, the year, and the designer. The .925 stamp is reserved for sterling silver, and refers to the silver content, at 925/1000 or 92.5 percent silver. If it was marketed as platinum, chances are you got ripped off and were sold a silver ring, or the ring is silver and plated with another metal, such as rhodium or platinum. Some items that appear to be gold but have the 925 stamp are made of gold-plated sterling silver. Identify platinum by using this list: Plat 900 PLAT 950 PLAT 10% IRID PLAT 10% IRID 90% PLAT COPLAT Identify Palladium by the marking PD.