The short answer
Only karat gold (10K, 14K, 18K) is gold alloy all the way through, whether the piece is solid or hollow. Gold-plated, gold-filled and vermeil pieces are real gold over a different metal; what separates them is how much gold the outer layer must contain. In the United States the Federal Trade Commission sets the minimums: a gold-plated (electroplated) layer must be equivalent to at least 0.175 microns of fine gold, a gold-filled layer must make up at least 1/20 of the metal’s total weight, and vermeil must be sterling silver under 10K or better gold equivalent to at least 2.5 microns of fine gold.
That matters because a layer can wear through and an alloy that runs all the way through cannot. For a piece you wear every day, karat gold has no different metal underneath to show. For occasional wear at a lower cost, plated, gold-filled or vermeil pieces are legitimate choices, as long as you know which one you are buying.
| Type | What it is | Gold layer rule (FTC) | What is underneath |
|---|---|---|---|
| Karat gold (10K, 14K, 18K), solid or hollow | A gold alloy throughout | No layer; the karat applies to the whole piece | The same alloy |
| Gold-plated (electroplate) | Gold alloy of 10K or more deposited electrically | At least 0.175 microns of fine-gold equivalent | Another metal |
| Gold-filled | Gold alloy of 10K or more bonded mechanically | At least 1/20 of the total metal weight | A base metal |
| Vermeil | Gold-coated sterling silver | 10K or better, at least 2.5 microns of fine-gold equivalent | Sterling silver only |
The rules quoted here come from the FTC’s Guides for the Jewelry, Precious Metals, and Pewter Industries (16 CFR Part 23), as revised in 2018. Every IMPERVORA product named below was available to order at the time of writing, and the facts given come from its own listing.
Karat gold: gold all the way through
When a piece is 14K gold, the karat describes the whole piece. Under 16 CFR 23.3, the word “gold” on its own should only describe 24 karat gold, and a gold alloy should carry its karat immediately before the word, as in “14K Gold”. Our guide to 10K vs 14K vs 18K gold explains what each karat contains.
“Solid” is a separate question. A chain can be karat gold throughout and still be hollow inside its links. The FTC says hollow pieces should be disclosed as such and should not be described as “solid”. You will also see “semi-solid”, which sits in between. Two of our chains show the difference:
- The 14k Yellow Gold Classic Miami Cuban Solid Chain (9.20 mm) is described on its listing as formed from solid gold rather than hollow tube, at an approximate weight of 144.3 g.
- The 14k Yellow Gold Semi Solid Miami Cuban Chain (5.00 mm) is described as having partially hollowed links, so it wears lighter, at about 15.4 g, and is less forgiving of a hard knock than solid construction.
Both are 14K gold. Only one is solid. Where one of our listings does not state solid or hollow construction, we do not describe it either way.
Gold-plated: a thin electroplated layer
The FTC allows “Gold Plate” or “Gold Electroplate” when the layer is gold alloy of at least 10 karat, covers all significant surfaces, and has a minimum thickness equivalent to 0.175 microns of fine gold. A layer of at least 2.5 microns may be called “Heavy Gold Electroplate”.
These are minimums, so “gold plated” alone tells you nothing about how far above them a piece is. And a karat in front of “plated” describes the plating, not the amount of gold. “18K gold plated” means the thin layer is 18K alloy; it does not make the piece 18K gold. Thickness is measured as fine-gold equivalent: the FTC notes that 1 micron of 12 karat gold counts as half a micron of 24 karat gold.
Gold-filled: a bonded layer measured by weight
Gold-filled bonds a layer of 10K or better gold alloy to a base metal by a mechanical process, not by electroplating. The FTC Guides allow the term “Gold Filled” when that layer is at least 1/20 of the weight of all the metal in the piece. Below that, down to 1/40, the terms are “Gold Plate”, “Gold Overlay” or “Rolled Gold Plate”, with the karat of the layer stated before the term.
The rule is a weight ratio, not a thickness, so by trade convention you will often see it stamped as a fraction and a karat, such as “1/20 14K GF”. If 1/20 of the metal is 14K alloy, and 14K is 58.5% gold, the piece is roughly 3% fine gold by weight. A solid 14K piece is 58.5% gold throughout.
Vermeil: defined by its base, not just its layer
Under 16 CFR 23.4, vermeil is sterling silver coated on all significant surfaces with gold or gold alloy of at least 10 karat, at a minimum thickness equivalent to 2.5 microns of fine gold. That is about 14 times the electroplate minimum.
Both conditions must hold. Gold over brass or copper is not vermeil, however thick the gold. And sterling silver with a thinner layer is gold-plated sterling silver, not vermeil; if the thickness is not stated, it cannot be confirmed as vermeil. The FTC also says that if a base metal such as nickel sits between the silver and the gold, that layer has to be disclosed.
Why plated pieces change colour
Any layer wears where it meets friction, such as a ring’s underside or chain links. Once the gold thins, the metal underneath shows. On sterling silver that metal can tarnish and darken; on other base metals it may discolour or mark the skin. Buyers of worn plated jewelry often report a faded finish, chipped spots, or a piece that turned dark or green.
How long a layer lasts varies with its thickness, how often you wear it and your skin chemistry. The FTC Guides call for “reasonable durability” but set no lifespan, so be cautious of any promised number of months. The American Academy of Pediatrics notes that nickel is commonly used in jewelry and as an alloy to harden more expensive metals such as gold. If you have a nickel allergy, ask what the base metal and any under-layer are before you buy.
How to read a listing or a stamp
- A karat immediately before “Gold” with no other qualifier, such as “14K Gold”, means a gold alloy throughout.
- “Gold Plated”, “Gold Electroplate” or “GEP” means a surface layer. Look for the karat of the plating and, ideally, a thickness in microns.
- “GF” with a fraction, such as “1/20 14K GF”, means gold-filled. “RGP” with a fraction, such as “1/40 12K RGP”, means rolled gold plate, a bonded layer whose share of the metal weight is given by the fraction and can be as low as 1/40.
- “Vermeil” should mean sterling silver underneath. “925” is the usual sterling mark.
- “Gold tone” or “gold colour” describes a colour only. It makes no claim that the piece contains gold.
- For chains, look for “solid”, “semi-solid” or “hollow”. If none appears, the construction has not been stated.
If something is missing, ask: What is the base metal? What karat is the gold layer, and how thick is it in microns? Is there a nickel or other base-metal layer under the gold? For a chain, is it solid, semi-solid or hollow? If a seller cannot answer, treat the missing detail as unknown rather than as a yes.
Which should you choose?
- For a ring or chain you will wear every day, karat gold is the practical choice. There is no layer to wear through, and our care guide by metal and stone covers what does change with wear.
- For earrings or occasional pieces, plated, gold-filled or vermeil can make sense; plan on re-plating as future maintenance.
- For a chain, check construction as well as karat; our guide to choosing a chain for a pendant covers width, link style and clasps.
What IMPERVORA sells
Our karat gold listings state the karat in the title, and the two Cuban chains above also show it in a Metal Stamp field. We also sell sterling silver, and some of those pieces are gold-plated, such as the Sterling Silver Yellow Gold Plated Round Link Paperclip Chain (5.20 mm), whose listing names 925 sterling silver as the metal. These listings do not state a plating thickness, so we cannot confirm the vermeil standard and describe them only as gold-plated sterling silver. At the time of writing we do not list any vermeil or gold-filled pieces.
If you are unsure what a piece is made of, our Concierge can check the manufacturer’s specification before you order. Unworn pieces in their original packaging can be returned within 30 days of delivery (the return must be postmarked within that window); custom, engraved and personalised pieces, pierced earrings and final sale items are excluded. The full terms are in our return and refund policy.
