GF (gold filled)
A layer of karat gold bonded to another metal, making up at least a twentieth of the article’s metal by weight.
Easily confused with
How to read it
The FTC’s jewelry guides reserve gold filled, like rolled gold plate and gold overlay, for a gold alloy layer applied by a mechanical process, with the karat of that layer marked first. Gold filled is the heaviest of these: the plating has to make up at least 1/20th of the weight of the metal in the whole piece, which is what a mark like 1/20 12K GF states. The Stamping Act names gold filled among the plated goods its rules cover.
Also searched as: 1/20 12K GF, G.F., GF, gold filled.
A stamp is a claim about the metal, made by whoever struck it. This page says what each mark means under the rules that define it; it doesn’t test or value anything.
What’s the difference between gold filled and gold plated?
How the gold is applied and how much of it there is. Under the FTC’s guides, gold filled is a mechanically applied layer of at least 1/20th of the metal’s weight; gold plate made by electroplating needs a layer only 0.175 microns thick. Rolled gold plate is the same mechanical process as gold filled, with a thinner layer.
More jewellery marks
Sources
- Guides for the Jewelry, Precious Metals, and Pewter Industries (16 CFR Part 23), 16 CFR Part 23 (1 January 2021 edition), Federal Trade Commission, published by the U.S. Government Publishing Office, § 23.4(b)(6), § 23.4(c)(2)
- Falsely Stamped Gold or Silver or Goods Manufactured Therefrom (15 U.S.C. chapter 8), 15 U.S.C. 291–300, the National Gold and Silver Stamping Act (2021 edition), U.S. Government Publishing Office, § 297
Last reviewed September 27, 2026 by Rory Hansen. How we research