Vermeil is a legally regulated term that refers to a certain kind of quality jewellery. To be legally called "vermeil" internationally, the jewellery piece must meet ALL of these conditions:1. Have sterling silver as its base material. Sterling silver is an alloy made of 92.5% pure silver and 7.5% other materials, and is a standard material used in high quality jewellery (versus, e.g. brass or copper).2. Be plated in gold that is at least 10k (10 karats). That means the gold is at least 41.7% gold content.3. Have gold plating that is at least 2.5 microns thick. A micron is 1/1000th of a millimeter.In other words, vermeil pieces are made with precious materials with heavy plating to ensure long-lasting wear.