What is gf on gold jewelry?

In gold jewelry, "gf" stands for "gold-filled," which is a term used to describe a specific type of jewelry construction. Gold-filled items have a layer of gold mechanically bonded to a base metal, typically brass, making them more durable and less likely to tarnish compared to gold-plated items. The gold layer in gold-filled jewelry must comprise at least 5% of the item's total weight, providing a more substantial and long-lasting alternative to solid gold.