How can you tell if costume jewelry is real gold?

To tell if costume jewelry is real gold, try placing a magnet near it. Genuine gold isn't magnetic, so if you notice any attraction, the piece is unlikely to be solid gold. Hallmarks, such as 14K or 10K, can also help you identify gold jewelry. However, keep in mind that, by definition, costume jewelry is usually made out of inexpensive materials. As a result, most costume jewelry brands don't use real gold. If they do, the gold is most likely plated, meaning that the jewelry is predominantly a base metal to which a thin layer of gold gets applied as a finish. A certified appraiser or experienced jeweler can also help you determine if your jewelry is gold. On 1stDibs, shop a large collection of gold jewelry.