In short
Flash plating is a color, gold plating is a layer, micron plating is a thicker layer, and none of them is gold you can sell. The US rule draws the line at 0.175 microns: below it a piece may only be called gold flashed or gold washed; at or above it, gold electroplate; at 2.5 microns, heavy gold electroplate, and on sterling silver, vermeil. "Micron plating" is a trade phrase for 1 micron and up, roughly six times the legal minimum and ten to thirty times a flash. On a ring worn daily a flash is gone in days, standard plating in weeks to a few months, 1 micron in months, 2.5 microns in about a year. The gold in a micron on a ring is worth about $1.64 at today's spot; you pay for bath time and honesty, not metal.
Contents
The words and the microns
| Trade name | Gold thickness | US legal label | What it is for |
|---|---|---|---|
| Flash, wash, gold tone | 0.03–0.15 µm | gold flashed or gold washed; may not be called plated | color on a display piece worn a few times |
| Gold plated, standard | 0.175–0.5 µm | gold electroplate, GEP, GP | fashion jewelry; earrings and pendants last, rings do not |
| Micron plating, 1 micron, 2 micron | 1–2 µm | still gold electroplate; the micron figure is a seller's promise | better fashion jewelry, replated pieces |
| Heavy gold electroplate, HGE | 2.5 µm and up | heavy gold electroplate | the top of plating; a year of daily ring wear |
| Vermeil | 2.5 µm and up over sterling silver, 10k or finer | vermeil | the same thickness on a precious base that can be replated |
| Gold filled | about 30–100 µm, 5% of weight | gold filled, 1/20 14K GF | a decade of daily wear |
| Solid | all the way through | 10K, 14K, 18K, 585, 750 | for life, and sellable by weight |
What the law requires, and where
In the United States the Federal Trade Commission guides set the vocabulary. Gold electroplate means a layer of gold of at least 10 karat with a minimum thickness throughout of 0.175 microns, about seven millionths of an inch. Heavy gold electroplate means at least 2.5 microns, about a hundred millionths of an inch. A thinner coat may only be described as gold flashed or gold washed, and a piece where a nickel layer was laid over the gold and then washed again with gold is flashed too, whatever the seller says. Vermeil is the same 2.5 micron minimum of 10 karat or finer gold, on a base of sterling silver. There is no legal meaning of "micron plating" or "1 micron" in the US; it is a promise, and a seller who makes it should be able to say who measured it.
Britain treats a plated piece as its base metal. Gold plated silver is hallmarked as silver, and the government guidance says the gold layer must be at least 375 fineness and should not exceed 2 microns; above that the description changes. So a British "18ct gold plated silver ring" is thin by rule, and a British vermeil-style piece is described as silver gilt. The point for a buyer on either side: "gold plated" is a legal word about a minimum, not a measurement, and the minimum is very small.
Thickness to months
| Thickness | Ring worn daily | Bracelet or chain | Earrings, pendant |
|---|---|---|---|
| 0.05–0.15 µm, flash | days | weeks | a season |
| 0.2–0.5 µm, standard | weeks to 3 months | 2–6 months | 1–3 years |
| 1 µm | 3–6 months | 6–12 months | 2–4 years |
| 2.5 µm, heavy plate or vermeil | 6–18 months kept dry | 1–3 years | 5–10 years |
| 30–100 µm, gold filled | 3–10 years | 10 years and more | decades |
Where a piece rubs decides everything. A ring loses its layer on the palm side, against door handles and steering wheels, in a fraction of the time the same layer lasts on a pendant hanging still. That is why sellers' "lasts one to five years" is true and useless: it depends on the item, not the brand. The vermeil page gives the item-by-item ranges for the 2.5 micron layer, and the water page explains why the towel does more damage than the shower.
Micron plating and the engineering standard
Plating shops measure in microns because industry does. The engineering standard for gold coatings, ASTM B488, defines thickness classes of 0.25, 0.5, 0.75, 1.0, 1.25, 2.5 and 5.0 microns, and purity types of 99.0, 99.7 and 99.9% gold, for connectors and instruments where a coating has to survive thousands of insertions. Jewelry plating borrows the vocabulary: a "1 micron" chain is a Class 1.0 coating in that language, four times the US legal minimum for jewelry, and 2.5 microns is the class that vermeil and heavy plate share.
The standard also explains the itch. For every class except the thickest, it requires a nickel underplate when the base is copper or brass, because nickel makes gold adhere and stay bright. Jewelry platers do the same, which is why so many plated earrings carry a nickel layer that reaches the skin the moment the gold wears through. Palladium is the nickel-free barrier; a seller who states it is a seller who knows the bath. The nickel page covers the reactions and the ten-dollar test.
What a micron costs in metal: on a ring with about 6 square centimeters of surface, one micron of gold weighs about 0.012 grams, worth $1.64 at today's spot of $141.74 per gram. Even at 5 microns the gold is under $8.21. Thick plating costs more because the piece hangs in the bath longer and the shop has to measure it, not because of the gold.
PVD and IP coatings on steel
Gold-colored stainless steel is not electroplated. It carries a physical vapor deposition coating, sold as PVD or IP: in a vacuum chamber a hard ceramic layer, usually titanium nitride, is deposited on the steel and tinted gold, and often finished with a whisper of real gold alloy on top. Published decorative structures run about 1 micron of titanium nitride under a few hundredths of a micron of gold; the gold is there for color, the nitride for hardness. That is why a PVD chain survives showers and years of friction that would strip electroplate, and also why it contains no gold worth mentioning and cannot be sold as gold.
"18k gold PVD" describes the karat of that surface film, not a quantity. When PVD fails it thins to grey steel at the clasp and the links under the chin rather than turning pink or green, because there is no brass underneath. The plated versus steel page compares the two for daily wear and water.
How to spot flash in a listing
- No microns. A seller with a thick layer says so, because it costs more. "Gold plated" or "18k gold plated" alone, with no thickness, is the low end by default.
- Price against metal. A "14k" chain for the price of lunch is plated; a plated chain with a price that suggests gold is flashed brass dressed up. The price page gives what the gold alone would cost.
- Weight. Brass is 8.5 grams per cubic centimeter, 14k gold about 13. A plated brass chain weighs roughly two thirds of a solid one of the same size; the chain weight calculator gives the solid figure to compare.
- Color. Flash is often too even and slightly orange, because it is a tinted film over a bright nickel or brass polish; heavy plate looks like the gold alloy it is.
- The edges after a week. Flash shows base metal at the edges and the clasp within days of wear; the seller's photos never do.
- The stamp. GP, GEP, HGE and RGP mark a layer; a karat mark with no maker's trademark beside it is not a lawful US quality mark, and on a plated piece it is a lie. The decoder reads them all.
What to ask, and when to replate
Four questions sort plated jewelry in a minute: how many microns, what karat is the layer, what is the base metal, and what is the barrier between them. Palladium barrier, sterling base, 2.5 microns and up is a piece worth buying for earrings and pendants and worth replating later. Nickel barrier, brass base and no thickness stated is a piece to buy for a season and retire. Replating is a real service for sterling and gold-filled bases: a jeweler cleans, re-barriers and plates to 1 to 3 microns for a fixed fee, and the piece comes back as new. Replating brass is rarely worth the fee; the base pits and the new layer follows the pits.
For anything worn daily and expected to last, the arithmetic on the layers guide points the same way every time: gold filled at tens of microns, or thin solid gold, costs more once and less per year than any plating rebought or replated.
Questions people ask
What does flash plated mean?
A gold layer too thin to be called plated: under 0.175 microns in the US rule, often a few hundredths of a micron, applied for color. It wears off a ring in days and an earring in a season, and legally it may only be described as gold flashed or gold washed. The base underneath is brass or nickel-plated brass, and the gold in it is worth less than a cent.
Is flash plated jewelry real gold?
The film is real gold, but there is so little of it that the piece is base metal by any measure: on a ring, a flash of 0.1 micron is about a thousandth of a gram. It cannot be sold as gold, has no scrap value, and turns skin green when it wears through. Buy it as costume jewelry at a costume price.
What is micron gold plating?
Plating sold by its thickness: 1 micron, 2 micron, 3 micron, meaning that many thousandths of a millimeter of gold. It is four to twelve times the US legal minimum for the word plated and lasts proportionally longer, months on a ring and years on earrings. The figure is the seller's promise, not a legal category, so buy it from a seller who can say who measured it.
How thick should gold plating be to last?
For earrings and pendants, 1 micron gives years; for a bracelet or chain, 2 to 3 microns for a year or more; for a ring worn daily no plating lasts long, and 2.5 microns buys six to eighteen months kept dry. Below 0.5 microns, expect a season on anything that rubs. For a ring meant to last, gold filled or solid gold is the honest answer.
Is 1 micron gold plating good?
It is good plating: four times the US legal minimum and enough for earrings and pendants to keep their color for years. On a ring it is three to six months of daily wear. The gold in one micron on a ring is worth about $1.64 at today's spot, so the extra price of 1 micron over standard is process, not metal; pay it for the durability, not as an investment.
What is the difference between gold plated and vermeil?
Thickness and base. Vermeil is a legal term in the US for at least 2.5 microns of 10 karat or finer gold over sterling silver; gold plated needs only 0.175 microns over any base, usually brass. Vermeil can be replated by any jeweler because the silver underneath is worth keeping; plated brass is rarely worth replating. Mejuri-style vermeil at 2.5 microns lasts years on earrings and about a year on a daily ring.