Sterling silver turns black or tarnishes due to a chemical reaction caused by contact with sulfur or hydrogen. Some foods or everyday items containing sulfur can cause tarnishing, but even polluted air can turn sterling silver black.Know More
Pure silver does not tend to tarnish. Sterling silver, however, is more susceptible to tarnish because it is a combination of silver and other more reactive metals such as copper. The sterling silver alloy may tarnish more easily than pure silver, but has far more uses than pure silver as it is far more durable. While tarnish is unavoidable, steps can be taken to reduce the amount of tarnish and prolong the life of sterling silver.
Avoid contact with sulfur-heavy items and foods. Latex gloves, wool and elastic items contain higher levels of sulfur and tarnish sterling silver faster. In addition, eggs, salad dressings and onions also speed up the tarnishing process. Even avoiding these types of items does not entirely prevent sterling silver from tarnishing, however. Sulfur or hydrogen produced by fossil fuels and burning coal or wood eventually cause tarnishing in most industrialized areas. The best way to prevent sterling silver from turning black is to perform regular maintenance. Clean sterling silver with a silver polishing cloth and occasionally a silver polishing compound to keep the tarnish from accumulating.Learn more about Precious Metals & Gems
Sterling silver is an alloy of metals that are not magnetic, and so it does not typically react when exposed to a magnet. Sterling silver's components may become magnetized when placed in a magnetic field but not to the same degree as a ferrous metal.Full Answer >
Hydrogen sulfide gas in the air causes silver jewelry to tarnish. This process happens quickly when silver jewelry is left out in the open, unprotected by a jewelry box. Tarnished silver jewelry turns a person's skin black or green when it is worn.Full Answer >
"Italy" denotes the country of origin, and "925" indicates silver at 92.5 percent purity, which is sterling silver. 92.5 percent purity means that the piece is comprised of 92.5 percent silver by mass and 7.5 percent of another metal by mass.Full Answer >
The quality mark for sterling silver is 925; 825 refers to a grade of continental silver. By law, all silver that is marked with the grade of its purity must also contain the name or registered trademark of the company that certifies this purity.Full Answer >