Green skin is copper — not nickel, and not an allergy. Here is which metals do it, why plating only delays it, and why "what is it plated over" is a better question than "is it gold."

Hypoallergenic is not a regulated word — no US agency defines it for jewelry and nobody has to prove anything before printing it on a box. Here is what it actually points at, why the answer almost always comes down to nickel, and the four things to check on any product page.