We've all owned a ring or necklace that went dark and dull after a few months in a drawer, or noticed a green mark on our finger after wearing something you loved all day. Its because some metals react with the air or our skin. Stainless steel isn't one of them.
Different metals, different reasons things go wrong
"Tarnishing" and "turning your skin green" get talked about like they're the same problem. They're not. They're two different reactions, happening to two different kinds of metal, and stainless steel doest have either .
Why silver goes dark
Silver tarnishing isn't about wear or age, it's a chemical reaction. Silver reacts with sulfur compounds in the air, and that reaction speeds up around humidity, lotions, perfumes, and even the natural oils on your skin. The result is a thin layer of silver sulfide sitting on the surface, that dark, dull coating you have to polish off to get the shine back. It's not damage exactly, it's just silver doing what silver does when it meets the everyday world. Which is why silver jewelry usually comes with a polishing cloth, and why pieces left untouched in a drawer come out looking worse than pieces worn every day.
Why brass and copper turn your skin green
This one's a different reaction entirely. Brass and copper contain copper, and when that copper meets sweat, its salts and mild acids dissolve tiny amounts of the metal from the surface. Those dissolved copper compounds transfer onto your skin, and that's the green or blue-green mark. It's completely harmless, just a surface reaction, not a sign anything's wrong with you or the jewelry. But it happens to some people more than others, since more acidic skin or heavier sweat speeds the reaction up, which is exactly why the same piece can stain one person and not another.
What stainless steel does instead
Stainless steel avoids both of these because of one thing: chromium. At around 10.5% chromium content or more, the alloy forms a thin, invisible layer of chromium oxide on its surface, created by the chromium reacting with oxygen in the air. That layer is what actually touches your skin, your sweat, and the air, not the raw metal underneath. And it's self-healing: scratch it, and it reforms almost immediately, so there's no exposed surface for sulfur to darken or copper salts to leach out from.
This is also the metal our PVD gold finish is bonded to. A finish that doesn't wear through only matters if what's underneath it doesn't wear. Stainless steel gives PVD a clean and lasting surface to bonding to.
