Gold plating is an electrochemical process that bonds a thin layer of gold to the surface of a base metal, most commonly brass, copper, or sterling silver. The piece is submerged in a solution containing dissolved gold ions, and an electrical current causes those ions to deposit uniformly across the metal surface. The result is a gold-toned finish that looks identical to solid gold at a fraction of the cost, which is why gold plating is one of the most common finishing techniques in both fine and fashion jewelry.
The thickness of the gold layer is measured in microns. Most fashion jewelry carries plating between 0.5 and 1 micron thick, while higher-quality pieces range from 1 to 3 microns. Anything above 2.5 microns is typically called “heavy gold plating” or “gold electroform,” and it wears significantly longer. Vermeil is a specific type of gold plating where the base metal must be sterling silver and the gold layer must be at least 2.5 microns thick, a standard regulated by the U.S. Federal Trade Commission. Gold-fill, by contrast, is not plating at all but a mechanical bonding process that uses a much thicker layer of gold and carries its own federal definition.
The durability of a gold-plated piece depends on three factors: the plating thickness, the base metal quality, and how the piece is worn. Friction from daily wear, exposure to chlorine, sweat, and cosmetics all accelerate the breakdown of the plating layer. When gold plating wears through, QJR's jewelers can strip the old plating, polish the base metal, and re-plate the piece to its original appearance. Re-plating is one of the most requested services for rings, pendants, and earrings that have lost their finish over time. Understanding what gold plating is and how it behaves helps you know when a piece is worth restoring and when the plating is simply doing its job.