16 CFR 23.5 - Misuse of the word
(a) It is unfair or deceptive to represent, directly or by implication, that an industry product is “vermeil” if such mark or description misrepresents the product's true composition.
(b) 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 7 and a minimum thickness throughout equivalent to two and one half (2 1/2) microns (or approximately 100/1,000,000ths of an inch) of fine gold.
7 See footnote 3.
It is unfair or deceptive to use the term “vermeil” to describe a product in which the sterling silver has been covered with a base metal (such as nickel) plated with gold unless there is a disclosure that the sterling silver is covered with a base metal that is plated with gold.
Exemptions recognized in the assay of gold filled, gold overlay, and rolled gold plate industry products are listed in the appendix.