Q: What's the difference between gold-filled and gold-plated?
A: Gold-plated jewelry has a smaller percentage of gold and goes through a different manufacturing process than gold-filled jewelry. To create gold-plated jewelry, a base metal goes through a series of processes and is eventually dipped into a bath of electroplating solution which contains gold. When an electric current is applied, an electrochemical reaction occurs and a thin layer of gold is deposited onto the metal. This layer is much thinner than the coating of gold that covers gold-filled jewelry, which goes through a process of mechanically bonding and heating the gold to the base metal.
While gold-filled components must include gold that is at least 1/20th the weight of the entire piece, gold-plated components can have gold that only makes up a very tiny percentage. As such, gold-plated jewelry items are more prone to tarnishing as well as having the thin layer of gold eventually rubbing off than similar products made from gold-filled. Because of the lower gold content, gold-plated items are generally less expensive than similar gold-filled products.