1, prepare a can of coke, put the oxidized necklace in a bowl, soak it in coke for half an hour, then take it out and clean it, and the necklace will change back to its original color.

2. Prepare a spoonful of salt and three spoonfuls of vinegar, mix them together, gently wipe the blackened part of the necklace with a cotton swab dipped in the solution, and keep wiping until the stains on the blackened part are wiped off.

3. Prepare a little toothpaste, wipe the black part of the necklace with a cotton swab dipped in a little toothpaste, and wipe it several times, which can also remove the black stains on the necklace. If the wiping effect is not good, you can wipe and polish it again with glasses cloth, which can make the necklace smoother and whiter.

4. Buy professional jewelry cleaning solution, clean the necklace according to the instructions, or clean the black stains on the necklace.

5, you can buy polishing sandpaper for jewelry, use sandpaper to polish the necklace a little bit, polish and polish it to eliminate black stains on the necklace.

6. Professional handling. Many people wear high-grade jewelry necklaces, all of which are blackened. Professional polishing and renovation are needed to solve the problem of necklace blackening, and the effect is better.