The easiest way to tell if something is real gold or gold plate is by holding a magnet up to the piece and waiting for the metal inside the piece to attract to it. If the piece is gold-plated, it is instantly connected to the magnet. If the piece is solid gold, it does not connect.
It is also possible to determine whether a piece of gold is real or gold plate by checking the piece for a manufacturer's hallmark and karat stamp. If the item is missing the stamp, it is most likely gold-plated. The difference between solid gold and gold plating is simple. Solid gold is gold in its purest form, and gold plate is a light coating of gold over metal. Gold-plated jewelry is often made with silver or copper and tends to leave a greenish stain on the skin. Gold-plated jewelry also produces a powdery gold substance as time wears on and the gold-plated coating begins to deteriorate.
Gold-plated jewelry is quite popular due to the fact that it resembles pure gold and is an affordable alternative, but the main problem with gold-plated jewelry is that it does not last long, and once the jewelry has lost its luster, there is no way to restore it.