15 U.S.C. §§ 291–293

It shall be unlawful for any person, partnership, association, or corporation engaged in commerce among the several States, Territories, District of Columbia, and possessions of the United States, or with any foreign country, to stamp any gold, silver, or goods manufactured therefrom, and which are intended and used in such commerce, with the words “United States assay”, or with any words, phrases, or devices calculated to convey the impression that the United States Government has certified to the fineness or quality of such gold or silver, or of the gold or silver contained in any of the goods manufactured therefrom. Each and every such stamp shall constitute a separate offense.

Any gold, silver, or goods manufactured therefrom after February 21, 1905, bearing any of the stamps, words, phrases, or devices prohibited to be used under section 291 of this title, and being in the course of transportation from one State to another, or to or from a Territory, the District of Columbia, or possessions of the United States, shall be forfeited to the United States, and may be seized and condemned by like proceedings as those provided by law for the forfeiture, seizure, and condemnation of property imported into the United States contrary to law.

Every person, partnership, association, or corporation violating the provisions of sections 291 to 293 of this title, and every officer, director, or managing agent of such partnership, association, or corporation having knowledge of such violation and directly participating in such violation or consenting thereto, shall be deemed guilty of a misdemeanor, and, upon conviction, be punished with a fine of not more than $5,000 or imprisonment for not more than one year, or both, at the discretion of the court.