Silver items only get better from socks. The bulges are polished to a high shine, and the depressions are covered with a natural patina. However, silver items can darken or yellow over time.
Silver acquires a yellow tint as a result of its interaction with hydrogen sulfide, carbon dioxide, oxygen and moisture in the air in the living room. Silver products are susceptible to atmospheric corrosion, which occurs due to air pollution with gaseous impurities. From this jewelry first tarnish, due to the formed surface film, which consists of hardly soluble compounds and causes interference coloration. Gaseous hydrogen sulfide, which is one of the components of the industrial atmosphere, can cause darkening and tarnishing of oxidized silver with the subsequent formation of silver sulfide. with a film thickness of 400 A, at first the silver turns yellow (with a thin layer of film), and over time becomes covered with a bloom of a dark brown, almost black color (a thick layer of plaque). The growth rate of the film thickness (sulfide layer) on silver items at a hydrogen sulfide concentration of more than 10-6% remains practically constant. When in a humid atmosphere of sulfur dioxide, silver sulfate additionally appears in the form of a loose product of corrosion. The increased content of hydrogen sulfide in rooms can be explained by its release from casein, which is used as a binder for pigments. Also, the source of the appearance of a yellow tint on products can be the release of sulfur from vulcanized rubber, which is used for gaskets in shop windows, in floor coverings, and finishing materials. There are many products that contain sulfur, which have an adverse effect when in direct contact with silver products. These can be some types of cardboard used for packaging, paper, textile materials. When interacting with them, yellow spots can form on silver. In dry air, silver items retain their color.
