Gold plated vs solid gold: how to tell the difference in five checks

What plating actually is

Gold plating is a thin layer of gold bonded to a base metal core, usually brass, copper or sterling silver. The layer can be very thin, a few microns on costume jewellery, or relatively thick on heirloom pieces. The thickness range for electroplated gold is typically 0.175 to 2.5 microns. Anything thicker is usually called gold-filled or rolled gold rather than plated. If a drawer holds a mix of both, it can go in one parcel: everything is tested and separated as part of selling unwanted jewellery.

Gold-filled (GF) and rolled gold plate (RGP) are heavier coatings, mechanically bonded rather than electroplated. They contain more gold than thin electroplate but are still not solid gold pieces. In the United States the US Federal Trade Commission rule, 16 CFR 23.3 allows "gold filled" only where the gold layer is at least 1/20th of the weight of the metal in the whole article. In the UK there is no equivalent statutory definition, but the markings are widely used. If the stamp says GF or RGP, the comparison of plated, filled and solid gold sets out how each is valued.

Hallmarks and marking conventions

A genuine solid gold piece sold in the UK should carry an assay office hallmark with a fineness number. 375 is 9 carat. 585 is 14 carat. 750 is 18 carat. 916 is 22 carat. 999 is 24 carat. Alongside the fineness mark you usually see the maker mark, the assay office town mark and a date letter.

Plated pieces are marked differently. Common abbreviations include GP (gold plated), GEP (gold electroplated), HGE (heavy gold electroplate), GF (gold-filled), RGP (rolled gold plate) and 1/20 (gold-filled ratio). Some plated pieces carry a carat number followed by "GP" or "EP", such as 18K GP. Many plated pieces, especially cheap costume items, carry no mark at all.

The weight feel test

Pick the item up. Compare it to a known-gold piece of similar size. Solid gold has a noticeable heft. A brass-cored plated piece feels light. A pewter-cored plated piece feels lighter still. The difference is more obvious on larger pieces, a solid 9 carat gold bangle feels substantially heavier than a plated bangle of the same dimensions.

Weight feel is not enough on its own. Some hollow solid gold pieces are deliberately lightweight. Some plated pieces over a copper or bronze core feel surprisingly heavy. Use the weight as a clue, not a verdict.

Magnet and wear-point checks

A strong magnet should not stick to either solid gold or most quality plated pieces. If the magnet pulls, there is iron in the core, which rules out both solid gold and decent plating. A clean pass tells you nothing on its own.

Wear points tell a different story. On a plated piece, the gold layer wears off first at the highest contact areas, the inside of a ring shank, the back of a watch case, the underside of a bracelet clasp. A duller, darker patch at those spots is the base metal showing through. On a solid gold piece, the same wear area looks the same colour as the rest of the metal.

Why GoldPaid still XRF-tests plated items

Plated pieces are XRF-tested here rather than set aside unread, because a mark is occasionally wrong. Pieces marked GP occasionally read as solid 9 carat under XRF, because the mark was applied wrongly somewhere in the trade chain. A 925 GP mark usually means sterling silver under a gold layer, and that silver is valued as silver. Gold-plated, gold-filled and rolled-gold pieces are not bought as precious metal, and GoldPaid pays nothing for them. The same non-destructive XRF metal test is also available on its own if you want an answer without selling.

Final offers depend on inspection, item weight, purity, hallmarks, stones, non-gold components, condition and the live precious-metal market. We XRF every item received, including plated and gold-filled pieces, so the truth of the metal is on record. If a piece is plated, gold-filled or costume, it is listed separately in the written offer at nil value and returned to you free with anything else you decline. There is no penalty for sending something that turns out to be plated.

Posting items you are unsure about

1. WhatsApp clear photos including the inside band or back of each piece to 07944 014111.
2. Note any marks you can see in the message, even GP marks or numbers without context.
3. Receive our reply and a prepaid Royal Mail Special Delivery label.
4. Bag each piece separately and pad inside a rigid mailer.
5. Drop off at a Post Office counter and forward the tracking on WhatsApp.
6. Read the written valuation when it arrives and decide at your own pace.