gold filled | ˈgōld fild
A term for a piece made up of a base metal, coated in a thick layer of gold (at least 10k and 1/20th of the total weight of the piece) bonded to its surface
A piece of gold-filled jewelry is one in which a piece of metal is coated in a thicker layer of gold bonded to its surface. The gold is at least 10K and must be 5% of the total weight of the piece to be considered gold-filled. Gold-filled jewelry is constructed in several layers. A core metal is used, often jeweler’s brass, followed by a layer of gold alloy bonded to the surface with heat and pressure. Unlike plating, there are legal requirements for how an object may be referred to as gold-filled. Gold plating is similar, but uses a different technique involving electroplating, and does not have the same minimum requirements as gold-fill. Both types of techniques will eventually lose their coating with wear and use.