METAL ALLOYS
Metal alloys have a mixture of metals from which they are created. Take brass for instance. Brass is an alloy that contains copper and zinc. Brass is a less expensive metal but is extremely sensitive to chemicals and moisture, thus may tarnish.
Now I know what you’re thinking: “But this ring is sterling silver, it isn’t copper or nickel!” Sterling silver is an alloy metal and because silver is a liquid, other metals must be added to it. Enter in…..copper and/or….nickel… among other types of metals. Even if that sterling silver ring were to be made with only 7% copper, it still has copper. And, if your biology is one that reacts to copper…. hello green.
Rarely, but not impossibly, a gold ring could cause a skin discoloration, and this is because gold is a very soft metal. Therefore, it is combined with a stronger metal to allow the finished product to hold its shape. If the stronger metal happens to be copper or nickel, then it is possible that the piece would cause a discoloration.
Ok, we’ve looked at the metals, what other factors play a part in whether or not a piece of jewelry will turn my skin green?