Delicate-looking yet strong this Argentium sterling silver air-rope chain. 1.8mm wide 1.3mm thick , 18" long with box clasp. Argentium silver contains germainium and other rare metals for tarnish resistance and bright color. Argentium Sterling Silver alloy is harder than traditional sterling silver, and purer. Argentium's hardness is resistant to materials that might normally damage the softer traditional sterling silver Argentium silver is a modern sterling silver alloy which modifies the traditional alloy (92.5% silver + 7.5% copper) by replacing some of the copper with the metalloid germanium . As it contains at least 92.5% silver content of the traditional alloy, it is still referred to as sterling silver. Traditional sterling silver tends to tarnish over time. By U.S. law, a silver alloy must contain at least 92.5% pure silver for the material to be labeled Sterling Silver. There is at least that much pure silver in Argentium so it is considered Sterling Silver. Argentium sterling can tarnish. To clean your Argentium sterling silver you can simply wash it in warm water mixed with a few drops of mild dishwasing soap. You do not want to use hot water as it can discolor the silver. If that doesn't remove the tarnish you can use a cotton swab or cloth to rub the areas that still have tarnish. Argentium is whiter and brighter than sterling silver.