I say, and with God's success: If gold is sold for gold directly, it must be equal in weight; otherwise, it would be usury. One way to resolve this issue is to have the customer initially purchase the gold, for example, and specify the amount for them, then sell the gold to the customer and specify the amount, and then pay the difference between them, whether to the seller or the buyer. However, it is a condition in this process that the bodies of both the seller and the buyer do not separate until everything is completed; because one of the conditions for selling gold is that the receipt and delivery occur in the same session; otherwise, they would fall into usury. And God knows best.