925 silver, that is, the purity of silver is 92.5%, which has the best hardness, luster and antioxidant properties. The chemical reaction between silver and sulfur molecules in the air produces black chemicals, and the chemical reaction between silver and toxins in the body occurs. You can try to apply a little toothpaste on the surface of the silver, then wipe it with a toothbrush dipped in warm water, and finally dry the wool with the whole., The use of silver cloth is one of the fastest and most convenient methods.Note: Data are all measured manually, please allow for an error of 1-3cm. Due to differences in light and display, there may be a certain color difference, which is subject to the actual object received.