According to the regulations, it is not allowed, and only the same material can be changed. Platinum diamond ring for platinum diamond ring, gold for gold. Generally, gold is convertible. Trade-in of gold is generally the following rules: when gold ornaments are exchanged for new ones, the depreciation fee per gram of 7 yuan must be paid, minus the loss of 1%, plus 20% new gold, and the production cost will rise by 20%. If the old jewelry exceeds 1 year, the service fee of 20 yuan/gram will be charged when it is replaced. For gold jewelry sold outside Zhou Dasheng, you need to add a fee of 40 yuan/gram, and in addition, you need to buy 20% of the original gold. In addition to deducting the loss, there is also a manual fee for trade-in If it is the gold ornaments sold in our store, deduct 8% of the loss; If the gold ornaments are not sold in our store, the loss will be deducted by 10%, but it will be added by 10 yuan per gram.