By Mark Salzwedel, Updated March 24, 2022
Unlike iron, silver does not rust; it tarnishes. Tarnish is a thin patina that forms when sulfur or sulfur‑containing gases react with silver. Even the sulfur gas that is naturally present in the atmosphere can contribute to tarnishing, and modern air pollution from coal combustion and gasoline engines releases additional sulfur dioxide, accelerating the process.
Many household soaps contain sulfur compounds, so wearing a silver chain while washing dishes or hands can speed up tarnish. In certain regions, groundwater contains high levels of magnesium sulfate (Epsom salt). When this reacts in the soil, it can produce hydrogen sulfide gas, which may also attack silver.
Standard silver polishes often use abrasives that simply scrape away the patina, leaving the chain thinner over time. A more effective, long‑term solution is the aluminum‑foil method: place the chain, a piece of aluminum foil, and a small amount of baking soda in a container of hot water. The sulfur in the tarnish migrates to the aluminum, restoring the silver’s shine without thinning the metal. Note that tarnish begins as a light yellow film and darkens with time; the longer it remains untreated, the harder it is to recover.
