At Mack & Myyles, we use quality gold-filled materials to ensure a long life of your jewelry. Gold filled is an actual layer of gold-pressure bonded to another metal. Gold filled is not to be confused with gold plating as filled literally has 100% more gold than gold plating. Gold filled is much more valuable and tarnish resistant. It does not flake off, rub off or turn colors. And is safe for people with sensitive skin. If your jewelry tarnishes with 365 days, we will replace it.