Brass is characterized by a high degree of polishing Will have a color like gold but As time is different from your personal physique, Or sweat, it will oxidize and turn black, Like silver, it will turn black. Some people who like to compare gold, After the jewelry is oxidized, it will feel very ugly and black. But some people will like this antique old black gold. These can be polished with copper oil or copper paste. Restore the original color of brass. Most of our copper comes from Thailand, Taiwan. When playing with Nepal or abroad, In the old market, look for brass in the store, The color of copper for each country Love different, This is why some are more gold, Others maintain the old sense of copper itself. #If you wear sterling silver or pure gold earrings without allergic reactions, wearing pure brass will not be allergic. Keep it in a dry place or use a zipper bag to protect the air from oxidative discoloration.