Is it permissible to take an estimated amount as compensation for stolen gold if it is greater than its real value, and is this amount lawful or unlawful?

If you do not know the quantity or value of the stolen gold, you must ask its owner about its weight and description, and ask specialists about its true value. It is not permissible for you to exceed that, as it contradicts the justice that Allah has commanded, even with enemies, as Allah Almighty says: "And let not the hatred of a people prevent you from being just. Be just; that is nearer to righteousness." And as He Almighty says: "So whoever has assaulted you, then assault him in the same manner that he assaulted you." The sin is on whoever exceeds, and you must return the excess to its rightful owners.