Vermeil is a combination of Sterling Silver and Gold commonly used as a component in jewelry. A typical example is Sterling Silver coated with 18K or 24K Gold. To be considered VERMEIL, the gold must be at least 10 karats (42%) and be at least 2.5 micrometers thick. In the US and various other countries, Sterling Silver covered first with a base metal (such as nickel) and than plated with Gold cannot be sold as vermeil without disclosing that it contains base metal. The Code of Federal Regulations 16, Part 23.5 defines Vermeil: "An industry product may be described or marked as 'vermeil' if it consists of a base of Sterling Silver coated or plated on all significant surfaces with Gold or Gold alloy of not less than 10 karat fineness, that is of substantial thickness and a minimum thicknes.