Identify jewelry markings by the type of precious metal content they symbolize. In the United States, jewelry manufacturers are required to inform the customer of the precious metal content in a piece of jewelry, which they often do by marking the inside of the piece. When using this method, the jewelry maker is required to include its trademark beside the metal content stamp.
A number followed by a "k" for "karat" indicates gold, with the karat number signifying the purity of the gold. Gold-filled or "GF" markings signify the jewelry is made of a base metal with a sheet of gold over it. "Vermeil" signifies sterling silver with gold-plating. "Sterling," ".925" and "925" signify the precious metal content of the jewelry is 92.5 percent silver. "Plat" or "platinum" is a jewelry marking that symbolizes the piece is at least 95 percent platinum, whereas "pall" or "palladium" signifies the piece is at least 95 percent palladium.
Other common jewelry markings include "Gold-plated" or "gold electroplate," "Silver-plated" or "silver electroplate," and "Nickel silver" or "German silver." These markings indicate a piece of jewelry has little to no precious metal content. Jewelry that doesn't contain precious metal isn't required to bear any markings.