Why Does a Silver Chain Turn Black?
Air Rust is called oxidation, because oxygen in the air starts to chemically react with the iron’s outer layers. Silver doesn’t oxidize, though; it tarnishes, which is the same as saying that it forms a patina. Tarnish is formed when sulfur or sulfur compounds come into contact with silver. Sulfur is present as a free gas in our atmosphere, but it is becoming more prevalent in sulfur dioxide in air pollution from the burning of coal and gasoline. Other Sources Some soaps contain sulfur compounds, so if you wear your chain while you wash your hands or your dishes, you may speed the tarnishing process. Some groundwater can have considerable concentrations of magnesium sulfate (epsom salt), and in some areas the magnesium sulfate reacts to become hydrogen sulfide, which can rise as a gas through the soil. Removing Tarnish Many silver polishes contain an abrasive that merely dislodges the tarnish to expose new, untarnished silver underneath. Using these substances will eventually make your
