Gold jewelry markings can describe metal purity, the manufacturing method, the maker or the place where a piece was tested. A mark such as 14K or 585 usually communicates gold content. Marks such as GP, GF, RGP or HGE describe a layer of gold over another metal. A logo or set of initials may identify the manufacturer rather than the purity.
A stamp is useful evidence, but it is not proof by itself that a piece is genuine. Marks can be worn, missing, altered or counterfeit. When identity or value matters, have the jewelry professionally tested.
Gold Jewelry Stamp Meaning Chart
| Mark | Common meaning | Approximate gold content |
|---|---|---|
| 10K or 417 | 10-karat gold | 41.7% |
| 14K or 585 | 14-karat gold | 58.5% |
| 18K or 750 | 18-karat gold | 75% |
| 22K or 916 | 22-karat gold | 91.6% |
| 24K or 999 | Nearly pure gold | About 99.9% |
| GP or GEP | Gold plated or gold electroplated | Gold surface over another metal |
| HGE | Heavy gold electroplate | Gold electroplate over another metal |
| GF | Gold filled | Mechanically bonded gold alloy layer meeting applicable standards |
| RGP | Rolled gold plate | Bonded gold alloy layer over a base metal |
| 925 | Sterling silver, not solid gold | May be the base beneath gold vermeil |
These are common interpretations, not a complete worldwide hallmark database. Marks vary by country, age and manufacturer.
What Do Karat and Fineness Stamps Mean?
Karat measures gold purity in 24 parts. Fourteen-karat gold contains 14 parts gold out of 24, with the remainder consisting of alloy metals selected for color, hardness and workability.
Millesimal fineness expresses purity in parts per thousand. That is why 585 corresponds to approximately 58.5% gold and 750 corresponds to 75% gold.
- 10K / 417: Lower gold content with a larger proportion of alloy metals.
- 14K / 585: A common balance of gold content and durability for everyday jewelry.
- 18K / 750: Higher gold content and often a richer yellow color.
- 22K / 916: High-purity gold that is typically softer than 14K or 18K alloys.
- 24K / 999: Nearly pure gold and generally too soft for many forms of everyday jewelry without special design considerations.
The exact alloy affects color and wearer sensitivity. White, yellow and rose gold can share the same karat mark because color does not determine purity.
What Is the Difference Between Karat and Carat?
- Karat, abbreviated K or kt: Describes gold purity.
- Carat, abbreviated ct: Measures gemstone weight. One carat equals 0.2 grams.
Some countries also use “ct” in historical gold-purity marks, so the object and origin matter when interpreting an older piece.
Hallmarks, Maker’s Marks and Assay Marks
The word hallmark is often used casually for any jewelry stamp, but the marks can perform different jobs:
- Purity mark: States karat or fineness, such as 14K or 585.
- Maker’s or sponsor’s mark: Identifies the manufacturer, responsible business or workshop.
- Assay mark: Indicates testing or verification by an authorized assay office in systems that use one.
- Country or regional mark: May indicate origin or the jurisdiction under which the piece was marked.
- Date letter: Some hallmark systems use a letter or symbol to help identify a testing year.
A hallmark is therefore not a second measurement of gold purity. It can be a group of marks that communicate identity, testing and origin in addition to fineness.
What Do GP, GF, RGP and HGE Mean?
GP or GEP: Gold plated or gold electroplated
These marks indicate a layer of gold over another metal. The piece should not be described as solid gold. The appearance and service life depend on coating thickness, wear, care and the underlying metal.
GF: Gold filled
Gold-filled jewelry is made with a gold-alloy layer mechanically bonded to a base metal. It is not filled with gold on the inside. Under current U.S. guidance, use of “gold filled” depends on the fineness and proportion of the gold-alloy layer.
RGP: Rolled gold plate
Rolled gold plate also uses a mechanically bonded gold-alloy layer, but the marked fraction and applicable standards differ from gold filled. Look for accompanying information such as a fraction and karat value.
HGE: Heavy gold electroplate
HGE means heavy gold electroplate—not “high-grade electroplating.” It still describes plated jewelry rather than solid gold.
Vermeil
In the United States, vermeil describes sterling silver covered with qualifying gold or gold alloy plating. A 925 or sterling mark may therefore appear on gold-colored vermeil jewelry because it identifies the silver base.
The Federal Trade Commission’s current Jewelry Guides in 16 CFR Part 23 provide the controlling U.S. guidance for these representations.
Where Are Gold Stamps Located?
Use bright, indirect light and a jeweler’s loupe or phone macro lens. Common locations include:
- Inside a ring shank
- On a clasp or small tag near a necklace clasp
- On the back of a pendant
- On an earring post, back or inner surface
- Inside a bracelet or near its clasp
- On a watch case rather than the removable band
Do not scrape, file or acid-test jewelry at home simply to expose a mark. Those methods can damage the finish or piece.
Does a Gold Stamp Prove the Jewelry Is Real?
No. A stamp is one piece of information, not an independent authentication. Counterfeit stamps exist, and legitimate jewelry may lack a readable mark because of age, repair, resizing, wear, manufacturing method or country of origin.
A professional jeweler may use visual inspection, weight and dimensions, electronic testing, X-ray fluorescence or carefully controlled acid testing. No single home test should be treated as conclusive.
Why Does Gold Jewelry Use Other Metals?
Pure gold is soft. Alloying it with metals such as silver, copper, zinc, palladium or others can change hardness, color and working properties. The alloy recipe—not merely the karat—also influences how jewelry reacts to wear and skin chemistry.
Lower-karat gold contains a larger percentage of non-gold metals, which can make surface reactions more noticeable. Learn more in our guide answering whether gold tarnishes.
Can Gold-Plated Jewelry Tarnish?
The gold surface itself is corrosion resistant, but a thin coating can wear or become porous enough for the underlying metal to react. Residue from skin products, sweat and cleaning agents can also discolor the surface without the entire piece being permanently damaged.
Use material-appropriate methods and understand the difference between cleaning and polishing jewelry. Aggressive polishing can remove part of a thin gold layer.
Frequently Asked Questions
What does 585 mean on gold jewelry?
585 indicates approximately 58.5% gold, commonly corresponding to 14-karat gold.
What does 750 mean on jewelry?
750 indicates 75% gold, equivalent to 18-karat gold.
What does 417 mean on gold?
417 indicates approximately 41.7% gold, corresponding to 10-karat gold.
What does 925 mean on gold-colored jewelry?
925 identifies sterling silver. A gold-colored piece stamped 925 may be gold-plated sterling silver or vermeil rather than solid gold.
What does GP mean after a karat mark?
GP commonly means gold plated. For example, 14K GP generally describes a 14-karat gold-alloy coating over another metal, not a solid 14K piece.
What does GF mean on jewelry?
GF means gold filled: a qualifying gold-alloy layer mechanically bonded to a base metal. It does not mean that the object’s interior is filled with gold.
What does HGE mean?
HGE means heavy gold electroplate. It identifies a type of gold-plated product rather than solid gold.
Does all real gold jewelry have a stamp?
No. A genuine piece may have no readable stamp due to age, wear, repair, size or origin. Conversely, a stamp can be counterfeit. Testing is more reliable when authenticity matters.
Can a gold stamp tell me what the jewelry is worth?
Not by itself. Value also depends on verified purity, weight, craftsmanship, gemstones, condition, brand, age and current market demand.
The Bottom Line
Begin by separating purity marks from process and maker’s marks. Numbers such as 417, 585 and 750 usually describe gold content. GP, GF, RGP and HGE describe how a gold layer relates to another metal. Initials or symbols may identify a maker or assay system.
Use the mark as a clue, then obtain professional testing before making decisions about repair, resale, insurance or inheritance. For related care guidance, compare gold behavior with our explanation of silver tarnish.
