A common problem that comes with sterling silver is tarnish. Pure silver does not typically tarnish, although it can get black residue when exposed to sulfur. Серебро 925 пробы, с другой стороны, can tarnish due to the way the alloy reacts to water and air. Silver that looks aged and dark in color means that it has oxidized. Some jewelers and consumers actually prefer this boho tarnished look.