Gold vermeil describes a specific type of composite material in jewelry. It comprises a base metal, typically sterling silver, coated with a layer of gold. The term “18k” indicates the purity of the gold layer used in this process. Gold purity is measured in karats, with 24k representing pure gold. Therefore, 18k gold signifies that the gold layer consists of 18 parts gold and 6 parts other metals, resulting in a gold content of 75%. The application of this relatively high-purity gold over sterling silver distinguishes the material from gold-plated items, where the gold layer is often much thinner and of lower purity.
The use of this technique offers a balance between aesthetic appeal and affordability. The rich color and luster of gold are achieved without the cost associated with solid gold pieces. Furthermore, sterling silver is a durable and hypoallergenic metal, providing a solid foundation for the gold layer. The thickness of the gold layer is also a critical factor; industry standards often require a minimum thickness to qualify as vermeil, ensuring reasonable longevity and resistance to wear. Historically, this method allowed for broader access to gold-toned jewelry, bridging the gap between costume jewelry and fine jewelry.