N.J. Stat. § 51:5-2
In any test for the ascertainment of the fineness of the gold or its alloy in any article mentioned in section 51:5-1 of this title according to the standards prescribed therein, the part of the gold or its alloy 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 fineness 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 gold and of its alloys contained in any article mentioned in said section 51:5-1 of this title, except watch cases and flat ware, including all solder, or alloy of inferior metal used for brazing or uniting the parts of the article (all such gold, alloys or solder being assayed as one piece), shall not be less by more than one karat than the fineness indicated 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. § 51:5-2