Understanding jewelry hallmarks is one of the best ways to identify metal purity, country of origin, and whether a piece is solid gold, gold-filled, plated, or made from precious metals like platinum or sterling silver. Look for purity numbers such as 10K, 14K, 18K, 22K, 24K, as well as .375, .585, .750, .900, .950, which appear commonly in both British and international hallmarking systems. British jewelry may also include symbols like the crown, the leopard’s head, or date letters, while international makers use a wide variety of purity and assay marks. In addition to solid gold and platinum, many vintage and antique pieces are marked with terms such as GOLD-FILLED, ROLLED-GOLD, R.G.P. (Rolled Gold Plate), or fractional marks like 1/20th 12K GF, which indicate a thick, durable layer of gold mechanically bonded to a base metal. These pieces can still hold excellent value. As with silver, some jewelry may be unmarked, especially older or handmade items, yet still test as precious metal — so when in doubt, professional testing by one of our specialists can help authenticate your jewelry.