N.J. Stat. § 51:5-4
In any test for the ascertainment of the fineness of any article mentioned in section 51:5-3 of this title, according to the standards therein prescribed, the part of the article taken for the test, analysis or assay shall be such part or portion as does not contain or have attached thereto any solder or alloy of inferior metal used for brazing or uniting the parts of such article, and, in addition to the aforesaid tests and standards, the actual fineness of the entire quantity of metal purporting to be silver contained in any article mentioned in said section 51:5-3 of this title, including all solder or alloy of inferior fineness used for brazing or uniting the parts of any such article (all silver, alloy or solder being assayed as one piece), shall not be less by more than ten one-thousandths parts than the fineness indicated, according to the aforesaid standards, by the mark stamped, branded, engraved or imprinted upon such article, or upon any tag, card or label attached thereto, or upon any box, package, cover or wrapper in which such article is incased or inclosed.
N.J.S. § 51:5-4