Vermeil (/ˈvɜrmɪl/ or /vərˈmeɪ/; French: [vɛʁˈmɛj]) is a combination of sterling silver, gold, and other precious metals, commonly used as a component in jewelry. A typical example is sterling silver coated with 14 carat (58%) gold. To be considered vermeil, the gold must be at least 10 carat (42%) and be at least 2.5 micrometres thick. In the US, sterling silver covered with a base metal (such as nickel) and plated with gold cannot be sold as vermeil without disclosing that it contains base metal.
The word “vermeil” is a French word which came into use in the English language, mostly in America, in the 19th century as an alternative for the usual term silver-gilt.
Vermeil can be produced by either fire-gilding or electrolysis. The original fire-gilding process was developed in France in the mid-18th century; however, France later banned the production of vermeil because over time artisans developed blindness due to mercury involved in the process. Today, vermeil is safely produced by electrolysis.
The White House has a collection of vermeil tableware kept on display (when not in use) in the Vermeil Room.
The US 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 thickness throughout equivalent to two and one half (2½) microns (or approximately 1/10000ths of an inch) of fine gold.”
The information above was taken from wikipedia.org