N.M. Stat. Ann. § 57-9-3.3
The owner of a store shall issue a serialized receipt for each purchase or statement of appraisal of gold, silver or platinum which shall contain the following:
E. the fineness of the precious metal in terms of karat for gold and sterling or coin for silver.
The merchant shall retain copies of each receipt or statement of appraisal for not less than one year.
History: 1978 Comp., § 57-9-3.3, enacted by Laws 1981, ch. 323, § 5.