Twenty grams and solid 18K through every link, which is the standard the other constructions are measured against. Antique Watch Chain, solid 18K gold, 20 grams
These two terms get used as though they were synonyms, and they describe constructions that differ by a factor of about sixty in how much gold they contain. Gold filled jewelry from 1910 routinely turns up looking almost unworn. Gold plated jewelry from 2019 often has brass showing at the edges already. The difference is not quality of manufacture, it is quantity of gold, and it is stamped on the piece if you know the letters.
What each one actually is
Gold filled is made by bonding a sheet of real karat gold to a base metal core using heat and pressure, then rolling the sandwich out. The gold is mechanically joined, not deposited, and the American standard requires it to be at least 1/20 of the total weight of the piece. That works out to a layer typically between 5 and 50 microns, which is thick enough to survive generations of wear.
Gold plated is made by depositing gold electrically onto a finished base metal object. The layer is usually 0.5 to 3 microns, which is measured in millionths of a metre. It is a colour rather than a construction.
Rolled gold, marked RG or RGP, is gold filled by another name, generally with a thinner layer, and it is the term used on most British and European pieces of the period.
Reading the marks
| Mark | Means | Gold content | Realistic life |
|---|---|---|---|
| 1/20 12K GF | Gold filled | 5% of weight, 12K gold | Generations |
| 14K GF, GF | Gold filled | Around 5% of weight | Generations |
| RG, RGP | Rolled gold plate | Bonded layer, thinner | Decades |
| GP, GEP, HGE | Electroplated | Microns | Months to a few years |
| 375, 585, 750, 916 | Solid gold | All of it | Indefinite |
Two traps live in these marks. "18K gold plated" describes the karat of the plating film and tells you nothing about how much there is. And a mark reading "14K" on its own means solid; a mark reading "14K GF" two letters later means something entirely different, which is why the whole stamp has to be read rather than the number at the front of it.
Finding out when there is no mark
Look at the wear points first, always: the underside of a ring shank, the inside curve of a bangle, the back of a clasp, the edge of a link. Plated work shows base metal there as grey, white or coppery, and it shows early. Gold filled work usually shows nothing at all, which is the whole point of it.
Then weigh it in your hand. Gold is dense, and a piece that feels light for its size is hollow, plated or both. A magnet identifies a steel core but proves nothing against brass, which is not magnetic. The full sequence, including why acid testing is a last resort on anything old, is in how to tell if gold is real.
Weight is the argument no plating can imitate. Twenty-five grams of chain feels like nothing else in the hand. Antique Watch Chain Necklace, 25 grams, 16 inches
What each is worth
Neither gold filled nor plated has a scrap value worth pursuing. Recovering gold from a filled chain costs more than the gold recovered, which is why refiners generally decline it. So the value of both is entirely as jewelry: design, maker, age, condition, wearability.
That is not a dismissal. Good Edwardian and Victorian rolled gold, Albert chains, lockets, bangles and brooches, are handsome, durable objects that have already survived a century, and they are the reason a great deal of genuine period design is still affordable. What they should never carry is a solid gold price. The honest way to buy them is knowing exactly what they are, which is the same rule that governs what gold is actually worth.
Which should you buy
For anything worn daily, solid gold or gold filled, and gold filled is a genuinely sensible choice for a chain you will wear constantly and do not want to worry about. For occasional wear, plated is fine if priced as costume. For anything you intend to keep or pass on, solid gold, because it is the only construction where nothing wears away.
Frequently asked questions
What does GF mean on jewelry?
Gold filled: a layer of karat gold mechanically bonded to a base metal core, legally at least 1/20 of the piece's weight in the United States.
What does 1/20 12K GF mean?
One twentieth of the total weight is 12 karat gold, bonded as a filled layer over a base metal core. It is a specific, enforceable claim.
Is gold filled the same as gold plated?
No. Gold filled carries roughly sixty times more gold, bonded mechanically rather than deposited electrically, and it lasts generations instead of months.
Is gold filled jewelry worth anything?
Not for its metal, since recovery costs more than the gold yields. Its value is as jewelry, and good period pieces are collectable and very wearable.
Can gold filled jewelry be resized or repaired?
Yes, though a jeweler must work carefully to avoid cutting through the gold layer at the join. Say what it is before handing it over.
Does gold filled turn your skin green?
Rarely, because the base metal is sealed under a thick layer. Plated pieces do it far more often, once the film wears through.
How can I tell plated from solid without a mark?
Check wear points for base metal showing through, and judge weight against size. An absent mark alone proves nothing either way.
Read next: What is gold vermeil? · Hollow vs solid gold · How to tell if gold is real
Line Evelin
