You can buy silver washing water, throw the black bracelet in this water for about 15 seconds, and then wipe it with a clean cloth, and the bracelet will become its original appearance. You can't soak the bracelet in this water for a long time. Soak for a long time and it will become darker. In this case, the bracelet is useless and will not return to its original appearance.

You can soak this bracelet in vinegar or some sodium hydroxide solution for a while, but don't soak it for too long, the black color will fade.

Buy that kind of professional silver cloth, and then use this cloth to wipe the bracelets. If the blackness of the bracelet is not so deep, it can be removed in this way, but if the blackness is very strong, it cannot be removed in this way.

You can use toothpaste. Toothpaste is a good helper to remove the blackness of silverware. Toothpaste is rich in fine calcium carbonate particles, and the friction of these particles can wipe off the silver oxide on the surface. Find a toothbrush, patiently wipe it with a little toothpaste for a while, and then wash it with clean water. It should be noted that after scrubbing with toothpaste, it must be washed with clear water, preferably pure water, not chlorinated tap water. Tap water containing residual chlorine can easily lead to the formation of silver chloride on the surface of silverware. When silver chloride is decomposed by light, it will still lead to the surface blackening of silverware.

The main reason why the silver bracelet turns black is that the oxide is generated on the silver, and the silver oxide is black, so the bracelet turns black. If you want to turn the blackened bracelet into its original appearance, try to remove this layer of silver oxide.