Jewelry labelling is one of the few areas of consumer commerce with real, quantified legal standards. The US Federal Trade Commission's Jewelry Guides at 16 CFR Part 23 don't tell you which piece to buy, but they do tell you exactly what each word legally obligates a seller to mean. Once you know the definitions, the marketing becomes legible.
It also helps to start with the thing nobody puts in the marketing copy.
Do the price maths first
As of mid-October 2026, gold is trading around $4,100–4,160 per troy ounce — roughly $132 per gram for 24K. Working down the karat ladder:
| Karat | Gold content | Approx. melt value per gram |
|---|---|---|
| 24K | 99.9% | ~$132 |
| 18K | 75.0% | ~$99 |
| 14K | 58.5% | ~$77 |
| 10K | 41.7% | ~$55 |
Run that against a $45 necklace and the arithmetic is immediate: 14K gold is about $77 per gram. A $45 necklace cannot be solid 14K gold. Not "probably not" — cannot, before we even count the labour of setting a stone and finishing the piece.
This isn't an accusation about anyone. It's the reason the vocabulary exists. Something has to be thinner than solid gold, and the law's job is to make that something say what it is.
The four legal categories
Solid gold. No coating, no base metal. In the US, a piece must be stamped with its karat — 10K is the legal floor to be sold as gold jewellery in the first place. 14K is 58.5% gold, 18K is 75%, and everything else in the alloy is whatever the alloyer chose: mostly copper and silver. That alloy content is not a flaw. It's why 14K is harder than 18K and why18K rings deform less over decades.
Gold filled. The gold layer must be at least 1/20 of the article's total weight (5%), at10K or better, mechanically bonded to a core under heat and pressure. Because the standard is weight-based, the layer isn't a thin coating — in practice it lands somewhere around 50–150 microns. Authentic pieces are stamped "1/20 14K GF". A maker marking "14k HGE" (heavy gold electroplate) or "14k GP" has not met the gold-filled standard, whatever the rest of the listing says.
Gold overlay / rolled gold plate. Same mechanical bonding, but the gold is only 1/40 of total weight. Legitimate, thinner, and required to say so.
Gold plated. Here's the trap. The FTC requires plated pieces to be labelled as plated rather than as gold, but it sets no minimum thickness for general "gold plated." To use the specific regulated term "gold electroplate," the layer must be ≥0.175 micron at ≥10K — which is roughly fourteen times thinner than vermeil's minimum. A "heavy gold electroplate" (HGE) needs the full 2.5 microns. So two pieces both described only as "gold plated" can legally differ by more than an order of magnitude in how much gold is on them, and both descriptions are accurate.
Gold vermeil. The outlier, and the most mispriced. To be called vermeil in the US, the base must be sterling silver (≥925) and the gold layer must be ≥2.5 microns at ≥10K or better, on all significant surfaces. The term cannot legally be used over a base metal, and if a nickel layer sits between the silver and the gold, it must be disclosed.
That base-metal requirement is the whole argument. A vermeil piece that eventually wears through leaves you holding sterling silver — a precious metal with intrinsic scrap value that can be polished and professionally replated, in principle, indefinitely. Gold-filled wears through to brass, which has neither property.
How long each one actually lasts
These are trade estimates rather than laboratory results, and wear life is driven more by friction and chemistry than by the label. Rough ranges for daily wear:
| Construction | Typical daily-wear life | Underlying failure mode |
|---|---|---|
| Flash plating on brass | 6 months – 2 years | Base metal shows, then tarnishes and can stain |
| Gold vermeil | 1–5 years (necklaces); 6 months – 2 years on rings | Wears through to silver — still a precious metal |
| Gold filled | 10–30 years | Gold thins at high-stress points, then brass is exposed |
| Solid 14K / 18K | Effectively indefinite | Surface scratches, polishable forever |
The honest weakness of each: gold-filled's brass core is the weak point at cut edges and stressed components like clasp springs and jump rings, where the layer can chip rather than wear gradually. Vermeil abrades more uniformly, which is why rings — the highest-friction category — are where vermeil underperforms relative to its reputation. And solid gold is soft: it scratches, and it holds onto those scratches, so it develops a patina of use rather than a uniform shine.
Five ways to check what you're actually holding
1. Read the stamp. "1/20 14K GF," "925," "14K," "585." No stamp on a piece of gold-coloured jewellery is itself the answer.
2. XRF spectrometry. This is the only genuinely conclusive test. It reads alloy composition through the surface without damaging anything. Independent labs and most high-end pawn dealers have one. If a seller of significant pieces won't tell you the spec, that tells you something too.
3. The magnet test. Gold and brass are both non-magnetic. If your piece clings firmly to a strong neodymium magnet, the core is steel or iron, and it is not gold filled. This is free, instant, and catches a specific and common category of misrepresentation.
4. Weight. Gold has a density of 19.3 g/cm³; brass is about 8.5. A genuine gold-filled piece feels noticeably heavier than a flash-plated brass piece of identical dimensions. It's not conclusive on its own, but combined with the stamp it's persuasive.
5. Look at the end caps. Gold-filled wire is drawn and cut, so the layer wraps continuously around the core. Poorly made pieces show a seam where plating pools or flakes at a join. Plated pieces routinely do.
And one to avoid: the scratch test. It's destructive and it tells you less than you'd hope — the colour underneath depends on the core, not the layer.
The cost-per-wear reframe
Price alone rewards flash plating. Price per year of daily wear doesn't:
| Construction | Typical price | Assumed life | Cost per year |
|---|---|---|---|
| Flash plated on brass | $15–$40 | ~1 year | $15–$40 |
| Gold vermeil | $45–$85 | ~3 years (with care) | $15–$28 |
| Gold filled | $35–$120 | ~15+ years | $2–$8 |
| Solid 14K | $280–$800+ | Indefinite | Negligible, plus resale |
The figures vary with how a piece is worn, and an expensive piece worn daily in the shower will beat a cheap piece worn carefully. But the shape of it holds: gold filled and solid win decisively on anything you wear daily, and cheap plating only wins on things you don't.
Five questions worth asking any brand
- What exactly is the base metal, and what's the gold layer?
- Is the gold layer weight-bonded or electroplated, and if electroplated, how many microns?
- If it wears through in a few years, what's underneath?
- Can it be professionally replated or refinished?
- Will you state the spec in writing on the product page?
A seller who answers those five without hesitating has nothing to hide. That's the real test — not the number of karats, which is the easiest thing in the world to print.
If you want the underlying reason any of this shows up as a skin issue rather than just a dull surface, read Hypoallergenic Jewelry: What Actually Makes a Piece Safe for Sensitive Skin. And if the reason you're reading this is that something already went green on you, start with Why Does My Jewelry Turn My Finger Green?.
Frequently asked
Is vermeil the same as gold plated?
No, and the distinction is legal, not marketing. Vermeil requires a sterling silver base and a minimum2.5-micron gold layer. "Gold plated" has no thickness floor under FTC rules at all.
Is gold filled really14K?
Only if it says so. The standard is "1/20 14K GF" — 14K, 5% by weight. A "1/20 10K GF" piece is perfectly legitimate and contains half the gold.
Can you tell by looking?
Not reliably. Appearance tells you almost nothing about thickness or base metal, which is exactly why visually identical pieces can differ by years of wear life.
Does gold filled turn your skin green?
Far less often than plated, but not never. Once the gold layer thins at a high-friction point, the brass core's copper can react with sweat. Vermeil doesn't have this failure mode, because what's underneath is silver.
Why is solid gold so expensive if it's only 75% gold in 18K?
Because you're paying for the alloying, the forming, the setting, the finishing, the polish, and the fact that the whole piece is that material. The metal is roughly half the retail price at current spot; the rest is everything else.
Does this apply to sterling silver?
The sterling standard is simpler: 925 parts per thousand pure silver,92.5%, with the remaining 7.5% typically copper. There's no coating sub-category — it's either sterling or it isn't.
References
[1] Guidelines for the Jewelry, Precious Metals, and Pewter Industries, 16 CFR Part 23 (US Federal Trade Commission). eCFR. Retrieved October 2026 from 
16 CFR Part 23 -- Guides for the Jewelry, Precious Metals, and Pewter Industries
[2] National Gold and Silver Stamping Act, 15 U.S.C. §§294–300.
[3] Daily spot gold price, mid-October 2026 (~$4,102–4,157/troy oz). Retrieved October 2026 from 
24K Gold Price Per Gram Today | Pure Gold Rate Chart and goldgrambars.com