All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
It is incumbent upon the debtor to proceed quickly in repaying debt to clear himself from liability before Almighty Allah and to avoid becoming one of the oppressors since Allah's Messenger (PBUH) said: "Delay in payment by a rich man is injustice. So, if one of you is referred for payment to a wealthy man he should accept the reference." [Agreed upon].
The borrower is also required to give back the loan in the same form he had taken it. If he took money then he must give back money and if he took gold then he must give back gold. This is because possession is established by reception. Thus, the person is liable for repaying the loan in the same form he had taken it.
Based on the above question, your husband (Asker`s) must give back that loan to you in gold because he is liable for the gold and not its value on the day he had borrowed it. Rather, stipulating repayment in value is a form of the prohibited usury. However, it better for this couple to reach an amicable settlement in order for love and mercy to prevail between them for Almighty Allah Says (What means): "If a wife fears cruelty or desertion on her husband’s part, there is no blame on them if they arrange an amicable settlement between themselves; and such settlement is best; even though men’s souls are swayed by greed. But if ye do good and practise self-restraint, God is well-acquainted with all that ye do." {An-Nisaa`, 128}. And Allah the Almighty Knows Best.