Neb. Rev. Stat. § 77-2704.66

(1) Sales and use taxes shall not be imposed on the gross receipts from the sale, lease, or rental of and the storage, use, or other consumption in this state of currency or bullion. (2) For purposes of this section: (a) Bullion means coins, bars, ingots, notes, leaf, foil, film, or commemorative medallions of gold, silver, platinum, or palladium, or a combination of these, for which the value depends primarily on its content and not the form; and (b) Currency means a coin or currency made of gold, silver, or other metal or paper which is or has been used as legal tender.