Is it permissible to sell a gold bar for manufactured gold, with payment for the manufacturing costs?

Selling manufactured gold for gold bullion while paying a manufacturing fee is prohibited. This constitutes usury of surplus (riba al-fadl). Similarly, if the transaction is not conducted hand-to-hand, it also becomes usury of delay (riba al-nasi'ah). When gold is exchanged for gold, it must be like for like, whether it is manufactured or in the form of bullion. The majority of jurists hold that pure gold, gold dust, and sound or broken gold are all equal in terms of permissible sale, provided there is equality in quantity, and it is prohibited if there is a surplus. The permissible scenarios are: exchanging a kilogram of gold for a kilogram of gold hand-to-hand, or selling the bullion for cash and then using that cash to buy manufactured gold, or buying raw gold and giving it to someone to manufacture it for a fee paid in cash.