N.M. Admin. Code § 19.2.2.55
In addition to annual rentals, the lessee shall pay royalty on production as determined by the commissioner and as specified in the notice of sale and the lease. For all minerals except special minerals, the royalty shall be no less than two percent of the gross returns less the actual and reasonable transportation and smelting or reduction costs up to fifty percent of the gross returns. Gross returns shall be based on the arm's-length sales price of the produced minerals and shall include, if applicable, all premiums, bonuses and other consideration of any kind received by the lessee for the minerals produced from the premises. The lessee shall calculate royalty for special minerals in exactly the same manner as for other minerals, except that the royalty percentage shall be no less than five percent of the gross returns.
N.M. Admin. Code § 19.2.2.55