1. oxidation: It may be due to long-term exposure to chemicals, such as cosmetics, shower gel and detergent. , causing the bracelet surface to oxidize and form rust spots.

2. The gold content is not up to standard: If the gold content of the bracelet does not reach 18K, the bracelet may be easily oxidized or the mark is difficult to remove due to the composition of the alloy.

If you want to remove the mark on the bracelet, you can try the following methods:

1. Where to buy a bracelet: You can take the bracelet back to the place where you bought it and ask a professional to help you clean it. This is usually the most effective method.

2. Cleaner cleaning: You can also try to use a special jewelry cleaner to clean the bracelet, but you need to pay attention to using the correct cleaner to avoid damaging the bracelet.

If the mark on the bracelet is still difficult to remove after trying the above methods, it is recommended to seek professional jewelry cleaning or repair services. At the same time, in order to prevent the bracelet from being oxidized or imprinted, it is recommended to avoid contact with chemicals as much as possible during use, and to maintain and clean it regularly.