What is gold-fill:
Gold-filled jewelry is jewelry composed of a solid layer of gold, mechanically bonded to a base of either sterling silver or some other base metal.
Most high-quality gold-filled pieces have the same appearance as high carat gold, and gold-filled items, even with daily wear, can last 10 to 30 years. The layer of gold on gold-filled items is 5 to 10 times thicker than that produced by regular gold plating, and 15 to 25 times thicker than that produced by gold electroplate.
To make gold-fill jewelry, multiple layers of solid gold are pressure-bonded to a core of high-quality jeweler’s brass using extreme heat. (Industry standards dictate that your piece must be 5% solid gold by weight.) The result is a thick layer of real gold and a durable, long-lasting product. Gold-fill jewelry is a great alternative to solid gold, as it offers the ideal balance of quality and value.