Silver can rust or tarnish over time because of exposure to moisture or sulfur in the air. Tarnish and rust can cause silver to darken and look like it is black. More »

Steel rusts because of chemical reactions that occur when it comes into contact with water and oxygen. Iron, one component of steel, combines with water and oxygen to produce hydrated iron (III) oxide, which is the chemi... More »

Bronze does not rust. The term "rust" refers strictly to the oxidation of iron and its alloys. Bronze is made primarily from copper and tin, with no iron added. More »

Silver tarnishes due to a reaction with sulfur in the air. Moisture and sunlight can also cause tarnish. More »

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 ... More »

All silver, plate, fill, sterling and fine tarnishes when its alloy metal, copper, is exposed to chlorides and sulfurs in the air. Argentium sterling silver is the most tarnish resistant because it contains more pure sil... More »

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 bla... More » Beauty & Fashion Jewelry & Watches Precious Metals & Gems