Rolled Gold, Gold Filled and Plated: Reading the Marks on the Layer
Between solid gold and gilt brass lie four or five distinct constructions, each with its own marks and its own lifespan. The difference between a piece that will outlive you and one that wears through in a year is a number stamped in the clasp.
Gold over base metal is not one thing. It is a family of constructions that differ by a factor of a hundred in how much gold they actually contain, and the trade marked them with reasonable honesty, which means the answer is usually stamped on the piece. Learning the marks takes ten minutes and settles most of the questions people ask about inherited jewelry.
The constructions, thickest first
Solid gold carries a fineness mark and nothing else: 375, 585, 750, 916, or 9K, 14K, 18K, 22K. See the fineness number guide.
Gold filled is a mechanically bonded layer of real karat gold, heat and pressure fused to a base metal core, with a legal minimum of 1/20 of the total weight in the United States. Marks read GF, 1/20 12K GF, 14K GF, 1/10 12K GF. This is a substantial layer, often 5 to 50 microns, and good gold filled from the early twentieth century still looks unworn today.
Rolled gold, marked RG, RGP or rolled gold plate, is the same idea with a thinner layer and, historically, a looser standard. British and continental work uses this term where American work says gold filled.
Vermeil is gold over sterling silver, with a modern minimum thickness of 2.5 microns and a requirement that the base be silver. Marks may say VERMEIL, or simply carry the silver standard with a gold surface.
Electroplate, marked GP, EP, GEP or HGE for heavy gold electroplate, is gold deposited electrically, typically 0.5 to 3 microns, which is measured in millionths of a metre and wears through with use.
Gilt and gilded work is covered separately in gilding through the ages, including the mercury gilding used before electroplating existed.
| Mark | Construction | Practical life |
|---|---|---|
| 585, 750, 14K, 18K | Solid gold | Indefinite |
| 1/20 12K GF, 14K GF | Gold filled, mechanically bonded | Decades of daily wear |
| RG, RGP | Rolled gold, thinner layer | Years to decades |
| VERMEIL | Gold over sterling silver | Years, thinner at wear points |
| GP, GEP, HGE | Electroplate, microns | Months to years |
Testing when there is no mark
Look at the wear points first: the underside of a ring shank, the edge of a bangle, the back of a clasp. Base metal showing through as white, grey or reddish is decisive, and it is why the wear points are the first place any dealer looks.
Magnetism identifies steel and some base cores, though brass and nickel silver are not magnetic, so a negative result proves little.
Colour at the join: plated work often shows a slight colour difference where two components meet, because the plating covers a solder line rather than a continuous metal.
Weight and sound: gold is dense, and a piece that feels light for its size is usually hollow, plated, or both. See how to tell if gold is real for the full sequence, including why acid testing should be a last resort on an antique.
What it means for value
Gold filled and rolled gold have no melt value worth collecting, since recovering the gold costs more than it yields. Their value is entirely as jewelry: design, maker, condition, wearability. That is not nothing. Good Edwardian rolled gold Albert chains, lockets and bangles are handsome, durable objects, and they are the reason a great deal of period design is still affordable.
The honest warning runs the other way too. A piece described as "gold" in a listing, with a mark reading GF or RGP, is not being sold dishonestly if the mark is shown, but the price should reflect the construction. Any listing where the metal is asserted rather than marked deserves the question, and any refusal to photograph the clasp deserves a second one.
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 total weight in the United States. It is much thicker than plating.
What does 1/20 12K GF mean?
One twentieth of the piece's weight is 12 karat gold, bonded as a filled layer over a base metal core.
Is rolled gold the same as gold filled?
Nearly. Rolled gold, marked RG or RGP, describes the same mechanical bonding but historically with a thinner layer and a looser standard than the American gold filled requirement.
What is vermeil?
Gold over sterling silver, with a modern minimum thickness of 2.5 microns. The base metal being silver rather than brass is what distinguishes it from ordinary plating.
Is gold filled jewelry worth anything?
Not for its metal, since recovery costs more than the gold recovered. Its value is as jewelry, and good period gold filled pieces are durable and collectable.
How can I tell plated from solid gold without a mark?
Check the wear points, the shank underside, bangle edges and clasp backs, for base metal showing through, and judge weight for size. Absence of a mark alone proves nothing either way.