Every one of these means a coating over base metal. All are legally honest, and all are read as gold by people who skip the letters.
Manufacturer's marks disclosing a plated finish, worldwide6 checks
This page exists because the most effective gold misrepresentation in jewellery is not a false number. It is a true number with two small letters after it, on a stamp two millimetres long, worn smooth by twenty years in a drawer.
18K GP, 14K HGE, 1/20 12K GF, 9ct RGP — every one of those marks is legally accurate, every one discloses that the gold is a surface layer over base metal, and every one is routinely read as though the letters were not there. That is not an accident of design; it is what the marks are for and how they are relied upon.
None of these products is a fraud in itself. Gold-plated and gold-filled jewellery is perfectly legitimate, sometimes very well made, and in the case of gold filled genuinely durable. The fraud is only ever in the selling, and the defence is a loupe and the habit of reading the whole stamp.
The marks form a ladder from a molecular film to a bonded sheet, and the differences in durability are enormous — from months to decades. The stamps that mean the least are often the most prominent.
Two things are worth internalising. Any mark containing the letter P for plate or plated, or the letters EP, means an electrodeposited layer. Any mark containing GF or a fraction such as 1/20 means a mechanically bonded sheet, which is a different and much better thing. Neither is solid.
| Mark | What it means | Typical durability |
|---|---|---|
| GP / GEP / EP | Gold electroplate — a thin electrodeposited layer | Months to a couple of years |
| HGE | Heavy gold electroplate — thicker plating | A few years |
| RGP | Rolled gold plate — bonded, but below the gold-filled threshold | Several years to decades |
| GF / 1/20 or 1/10 + karat | Gold filled — bonded sheet, 5% or 10% of weight in karat gold | Decades |
| Vermeil | At least 2.5 microns of ≥10k gold over sterling silver (US rule) | Years |
| 'Gold tone' / 'gold finish' | A colour description. No gold content implied at all | Not applicable |
| '18K over sterling' | Plated, and the base is sterling silver | Years; wears to silver-white |
| Bonded gold | A marketing term with no fixed legal meaning | Varies — ask for microns |
'Gold tone', 'gold colour' and 'gold finish' are the ones to watch in online listings. They are not metal claims and they carry no obligation to contain any gold whatsoever.
A stamp is a claim, not a property. These are ordered by how much each one settles about the metal underneath — and the first two need nothing but a loupe and good light.
The letters are usually smaller than the numbers and wear first. Put a loupe on the mark, follow it from end to end, and look for characters after the karat figure and for a fraction before it. On a worn piece, tilting under a raking light often reveals a ghost of letters that are no longer legible flat-on.
Plating fails at friction points, and the base metal beneath is a different colour. Look at the underside of a ring shank, the inside of a bangle, the back of a clasp, the crests of any texture, the edges of a bezel and the tips of claws. Yellow-pink means brass or bronze; grey-white means nickel or steel; bright silver-white means a sterling base, which indicates vermeil or gold-over-silver.
Plated jewellery is base metal, so it weighs what base metal weighs — brass at about 8.5 density against 14 karat gold's 13.1 and 18 karat's 15.5. A large, impressive piece that feels light is plated, hollow, or both. Handling one known solid piece calibrates this quickly.
Once plating breaches, the copper in the brass beneath oxidises. That produces green verdigris in crevices, a coppery bloom on the surface, and the familiar green mark on skin where a ring sits. Solid gold of any karat does not do this, and 9 carat only dulls rather than corroding.
For new jewellery this is the question that cuts through the marketing. Flash plating is a fraction of a micron. Decent plating is 1 to 3 microns. Vermeil requires 2.5 microns minimum over sterling in the US. Anything described as bonded, heavy or premium without a micron figure is being described rather than specified.
Plated and gold-filled pieces cannot be sized, soldered or heavily polished without breaching the layer, so a jeweller will usually refuse the work or warn you. That refusal is a reliable, free diagnosis from somebody with no incentive to mislead you.
The interesting thing about this category is that most of it is not counterfeit at all. The marks are honest, the products are legal, and the manufacturers have disclosed exactly what they made. What fails is the transmission — a resale listing that quotes the karat and omits the letters, a market stall that lets you assume, an inherited piece whose stamp is illegible.
Where genuine fraud does occur, it is usually the removal of the disclosure rather than the addition of a false claim: a stamp filed or polished so that only the karat number survives. Under a loupe that shows as an area of the surface that is smoother, brighter or slightly dished compared with the metal around it.
The other genuine fraud is descriptive: 'gold tone', 'gold finish' and 'gold coloured' in listings, which sound like understated honesty and are in fact statements about colour with no metal content implied at all.
Each of these is checked differently. The ones with their own page have enough that is specific to them to be worth reading separately.
Metal value first, because it is the floor and it is easy to calculate. Anything worth more than melt is worth it for the maker, the age or the design — never for the stamp.
| Mark | Metal value | What it is worth for |
|---|---|---|
| GP / GEP / EP | Nothing | Design and condition only |
| HGE | Nothing | Period design; working watches |
| RGP | Negligible | Vintage appeal |
| 1/20 or 1/10 GF | Notional; not economic to recover | Durability and design — good vintage GF is collectable |
| Vermeil | The sterling base only | Design, plus a few dollars of silver |
None of these has a metal floor, which is the practical difference from solid gold. Their value is entirely in design, maker and condition — and good Art Deco and mid-century gold filled is genuinely collected.
Lovenhall RingThe mark tells you what the metal claims to be. The instrument reads the setting and the stones together and gives a range to orient you — before anyone charges you for an appraisal.