Gold-plated, gold-filled, vermeil, and solid gold can all look identical in a product photo. The difference only shows up later—when plating wears off, when a buyer rejects a piece, or when a test stone suddenly turns green.

If you flip thrift finds, run a pawn counter, or simply want to protect yourself when buying jewelry, you need a way to separate surface gold from solid gold construction. This guide walks through the same checks professionals use: hallmarks, visual wear patterns, magnet and density tests, and finally scratch-stone plus acid testing to confirm what is really under the surface.

In this guide

• What “gold-plated,” “gold-filled,” “vermeil,” and “solid gold” actually mean
• Hallmarks and stamps that hint at plating vs solid gold
• Visual clues that give away plating and gold-filled construction
• Low-damage checks before you ever scratch a piece
• How to confirm with scratch-stone and acid tests
• When to escalate to density, electronic testers, or XRF
• FAQs for resellers, pawnbrokers, and collectors

1. What each type really means

Before you test anything, it helps to be precise about the vocabulary. A lot of online sellers casually call something “gold” when it is only gold-plated.

• Gold-plated — A very thin layer of gold electroplated over a base metal such as brass, copper, or zinc. The gold layer can be just a few microns thick and wears off quickly at contact points.
• Gold-filled (rolled gold) — A mechanically bonded layer of karat gold over a base metal core, usually brass. Regulations in many markets require a minimum gold-content ratio (for example “1/20 14K GF” means 1/20 of the total weight is 14K gold).
• Vermeil — Sterling silver (typically stamped 925) with a comparatively thick layer of gold plating. The base is precious metal, but the gold layer is still a surface coating.
• Solid gold (karat gold) — A homogenous alloy of gold and other metals throughout the piece, such as 10K, 14K, 18K, or 22K.

From a testing standpoint the key point is simple: plated and gold-filled pieces can show “real gold” reactions at the surface. Any test that never reaches below that surface layer can be fooled.

2. Hallmarks and stamps that matter

Hallmarks are not a guarantee, but they tell you what the piece claims to be and often give away whether it is plated, filled, or intended as solid gold.

Common purity marks for solid gold

• 10K, 14K, 18K, 22K, 24K
• 417 (≈10K), 585 (≈14K), 750 (≈18K), 916 (≈22K)

Silver or platinum bases you might see under vermeil

• 925 (sterling silver)
• 950 (common for platinum and some high-silver alloys)

Marks that often signal plating or filling

• Gold-filled: “1/20 14K GF”, “1/10 12K GF”, “GF” after the karat stamp, or older marks like “RGP” (rolled gold plate).
• Gold-plated: GP (gold plated), GEP (gold electroplated), HGE (heavy gold electroplate), or foreign equivalents like “Plaqué or”.
• Vermeil: “925” plus a karat mark, occasionally “VERMEIL”.

If a piece looks new and “gold toned” but carries no purity or construction stamps at all, many buyers treat it as costume until testing proves otherwise.

3. How plating and fill give themselves away visually

Experienced buyers can often spot plating and gold-filled construction before they ever pull out a test stone. They look where the jewelry wears down first.

• Edges and corners. Check ring shanks, clasp edges, and pendant corners. If bright “gold” faces sit above dull brassy edges or reddish copper spots, that is classic plating wearing through.
• Undersides and contact points. The backs of pendants, inside of rings, and chain links that rub against skin often show the base metal first as color shifts or patchy brassing.
• Color uniformity. Solid gold alloys tend to have consistent color throughout. Plated fashion pieces sometimes show slightly different shades between components, especially clasp vs chain.
• Tarnish and skin reaction. Green or black discoloration where the piece touches skin is common with copper and brass cores under plating; karat gold alloys are much more stable for most wearers.

None of this is a definitive test, but it helps you decide which pieces are almost certainly fashion/plated and which are worth a more invasive workflow.

4. Low-damage checks before you scratch

Owners get nervous when you mention “filing” or “scratching.” The right workflow squeezes as much information as possible out of non-destructive checks before you decide to cut into anything.

1. Hallmark and visual check. Read every stamp and inspect all the wear points above.
2. Magnet test. Gold and common karat alloys are non-magnetic. A strong pull from a neodymium magnet usually means steel or another magnetic base metal is present somewhere.
3. Weight / heft test. Compare the piece in your hand to a known solid-gold item of similar size when possible.
4. Simple density (for higher-value items). A water-displacement density test can tell you whether the overall build makes sense for the claimed karat.

5. How to confirm with scratch-stone and acid

Once you decide a piece is worth testing more aggressively, the goal changes: you want to know what is under the surface layer.

For full safety and step-by-step instructions, see How to Test Gold with Nitric Acid: Step-by-Step Safety & Accuracy Guide (2026).

A. Suspected gold-plated jewelry

1. Pick a hidden spot. Choose an interior edge or underside where a tiny mark will not be visible in normal wear.
2. File through the surface layer. Use a fine file or engraver to cut a small notch until you clearly see the cross-section.
3. Take two streaks on the touchstone — one from the untouched “gold” surface, one from the freshly exposed metal at the bottom of the notch.
4. Apply appropriate karat acid to both streaks. If the surface streak behaves like gold but the exposed streak dissolves quickly or turns green, the piece is almost certainly plated over base metal.

B. Suspected gold-filled jewelry

1. Cut a slightly deeper groove in a hidden area so the outer band and core metal are clearly visible.
2. Create separate streaks — one primarily from the outer gold layer, one that drags some of the core metal across the stone.
3. Test both streaks with acid. The outer-layer streak may hold up like 10K–14K gold; a streak dominated by the core usually reacts like brass.

C. Solid gold behavior

• Filing does not reveal a different-colored core.
• Streaks from multiple points behave consistently under the same karat acids.
• Density and weight match the expectations for the claimed karat.

Ready to test your own jewelry? Shop True Assay gold testing kits for professional-strength acids, touchstones, and full safety instructions in one package.

6. When to bring in density, electronic testers, or XRF

• Density testing. Great for checking whether a bracelet or chain’s overall build matches the story.
• Electronic testers. Handheld probes can provide a quick, non-destructive read, though they have limits around unusual alloys and thick plating.
• XRF analyzers. Non-destructive spectrometers used by larger pawn and refining operations.

For most True Assay customers, the sweet spot is a layered workflow: hallmarks and visual checks → magnet and weight → scratch-stone plus acid.

7. FAQs

Is gold-plated jewelry “real gold”?

The plating itself is real gold, but the underlying metal is usually brass or another base alloy.

Is gold-filled better than gold-plated?

Yes. Gold-filled jewelry has a much thicker and regulated layer of karat gold bonded to a base metal core, so it usually wears longer and contains more recoverable gold than ordinary plating.

Can I tell plated from solid gold without scratching?

Sometimes. Hallmarks, wear patterns, magnet response, and weight can strongly suggest plating or fill. When the item is valuable or the signs are mixed, a discreet notch and scratch-stone test is often the only way to be sure.

Will acid testing ruin my jewelry?

When done correctly on a touchstone with small streaks, the acid reacts on the stone, not on the visible surface of the jewelry. Filing or notching does leave a permanent mark, so always choose hidden areas.

How do pawn shops handle plated and filled items?

Pawn and metal buyers typically combine hallmarks, visual inspection, magnet testing, scratch-stone and acid, and sometimes XRF for higher-value deals.

Related reading: How to Test Gold with Nitric Acid · All True Assay Guides · Shop Testing Kits