1. Reasons for silver jewelry turning black Blackening of silver jewelry is a normal natural phenomenon, as sulfur and oxides in air and other natural media have a certain corrosive effect on silver. If silver jewelry is worn for a long time, sulfur and silver combine to form a black sulfide silver film on the surface of the jewelry, which begins to appear as small spots. After the sulfide phenomenon intensifies, it slowly spreads into sheets, forming what people usually call silver scale, which turns black and affects the surface gloss of the silver jewelry. People often mistake it for fading. The chemical reaction equation is: 4Ag+H2S+O2=2Ag2S+2H2O How to clean silver jewelry after vulcanization? Squeeze a little toothpaste and add a little water to make a rich foam. Wipe it with a soft cloth until it is bright. Brush the gap with a soft bristle toothbrush, and then rinse it with water. For complex components and chains, they can be put into toothpaste water with foam and gently rubbed repeatedly, and then washed with clean water. When the vulcanization is severe, professional silver washing water can be used for cleaning. Although silver washing water is claimed to not harm silver, it is still a chemical preparation and it is not recommended to use it unless necessary. 3. How to maintain silver jewelry on a daily basis? A better way to maintain silver jewelry is to wear it every day, because the body's oils can give silver a warm and natural luster (although there are exceptions, some people's sweat itself contains ingredients that make silver black). When wearing, use a soft cloth or silver cloth to wipe the surface of the silver jewelry every day to maintain its luster and dryness. When not wearing, gently wipe the surface with a soft cloth to remove moisture and dirt. Place it in a sealed bag to prevent oxidation and blackening of the silver surface in contact with air. Note: For more popular science on silver jewelry, please search online.