Hydrogen peroxide is a strong oxidizer, which can cause metals to corrode. However, the amount of damage depends on the type of metal and how long it's exposed to hydrogen peroxide. For example, gold is relatively resistant to corrosion, so it's unlikely to be damaged by brief exposure to hydrogen peroxide. On the other hand, silver is much more prone to corrosion, so even a short exposure could cause noticeable damage. In general, it's best to err on the side of caution. If you need to clean your jewelry with hydrogen peroxide, do so cautiously and only for a short time.