Understanding Jewellery Hallmarks

You just bought a vintage gold chain at an estate sale for $180. It feels heavy, looks right, but there’s a tiny stamp inside the clasp: “585.” Is that good? Bad? Did you overpay?

That stamp is a hallmark — a legal promise about what the metal actually is. Most people skip checking it. That’s how fake jewelry travels from market stalls to your drawer. Here’s exactly what those marks mean, how to read them, and what to do when they’re missing.

What Is a Hallmark and Why Does It Exist?

Hallmarks aren’t decoration. They’re a traceable guarantee of metal purity, backed by law in most countries.

The system started in London in 1300. King Edward I ordered that every piece of silver be tested and stamped by a guild of trusted goldsmiths. The word “hallmark” comes from Goldsmiths’ Hall, where the testing happened. Seven centuries later, the principle is identical: an independent assay office verifies the metal content, then stamps it.

Without hallmarks, you’re buying on trust alone. That $500 “18K” ring from an online reseller? Could be 10K gold with a thick gold plate. Could be brass with a gold wash that fades in six months.

What Hallmarks Actually Tell You

A full hallmark contains up to five separate marks:

• Sponsor’s mark — who made or imported the piece
• Metal purity mark — fineness in parts per thousand (e.g., 750 for 18K)
• Assay office mark — where it was tested
• Date letter — year of testing (varies by country)
• Traditional fineness mark — optional pictorial stamp (e.g., lion for sterling silver)

Not every country requires all five. The UK and India have strict systems. The US doesn’t require hallmarks at all — just a voluntary karat stamp, which means a “14K” stamp might be accurate, or might not.

The Three Numbers You’ll See Most Often

Ignore the letters at first. Focus on the three-digit number. That’s the fineness — parts of pure metal per thousand.

• 375 = 9K gold (37.5% pure). Common in UK and European costume jewelry.
• 585 = 14K gold (58.5% pure). The US standard for engagement rings.
• 750 = 18K gold (75% pure). Rich color, softer, more expensive.
• 916 = 22K gold (91.6% pure). Common in Indian jewelry. Very soft.
• 999 = 24K gold (99.9% pure). Pure gold. Too soft for daily wear.
• 925 = sterling silver (92.5% silver, 7.5% copper).
• 950 = 95% platinum or palladium.

If you see “585” on a European piece, it’s the same as US “14K.” Same metal, different numbering system.

How to Read a Hallmark in 30 Seconds

You don’t need a magnifying glass or a jeweler’s loupe. A phone camera with zoom works fine. Take a photo of the stamp, zoom in, and match it.

Step 1: Find the Stamp

Check the inside of rings, the clasp of necklaces and bracelets, the back of earrings, and the inside of bangles. On vintage pieces, stamps can wear down. If the surface is smooth but you see a faint rectangle or oval, that’s where the stamp was.

Step 2: Identify the Number

Look for a three-digit number. That’s your purity. Cross-reference with the list above. If you see “585” on a white gold ring, it’s 14K white gold — not silver.

Step 3: Check for the Assay Mark

If you see a leopard’s head (London), an anchor (Birmingham), or a castle (Edinburgh), the piece was tested in the UK. Those marks are hard to fake. If they’re crisp and clear, the metal is almost certainly genuine.

What If There’s No Stamp?

Two possibilities: the piece is pre-1900 (hallmarks weren’t always used), or it’s fake. For modern jewelry, no stamp is a red flag. Walk away unless you’re buying from a trusted seller with a return policy.

I once bought a “vintage” silver bracelet from a flea market for $40. No stamp, but the seller said it was “probably old.” Turned out to be nickel silver — zero silver content. The bracelet turned my wrist green in two hours.

Gold Hallmarks: 375, 585, 750, 916 — What Each One Means for Wear

Higher purity means more gold, softer metal, and higher price. Lower purity means more alloy metals (copper, silver, zinc), harder metal, and lower cost.

Prices fluctuate daily with the gold spot price. These are rough ranges for mid-2026.

Why 14K Gold Is the Sweet Spot

14K gold (585) hits the balance between purity and durability. It’s hard enough for daily wear — a ring won’t bend if you bump it against a doorframe — but still looks golden, not brassy. 18K looks richer but scratches easier. 9K looks paler and can cause allergic reactions in people with nickel sensitivity because the alloy contains more nickel.

White Gold vs Yellow Gold Stamps

White gold is yellow gold alloyed with palladium or nickel, then plated with rhodium. The hallmark is the same as yellow gold — “585” for 14K white gold. The rhodium plating is what gives it the silvery-white color. That plating wears off in 12–18 months and needs re-plating ($50–$100 at a jeweler).

Silver Hallmarks: 925, 800, 950 — and the Ones That Trick You

Silver hallmarks are simpler than gold. The vast majority of silver jewelry is 925 sterling silver. But there are traps.

Sterling Silver (925)

92.5% silver, 7.5% copper. The copper adds hardness — pure silver is too soft for jewelry. The stamp “925” or “STERLING” means the same thing. If you see “925” on a ring that looks gold, it’s silver with gold plating. That plating will wear off in 1–3 years depending on use.

800 Silver

80% silver, 20% copper. Common in antique European silver (German, Italian, Austrian). It’s darker, harder, and tarnishes faster than 925. Not better or worse — just different. If you inherit a piece stamped “800,” it’s silver, not a low-quality fake.

The Fake Stamps to Watch For

• “925” on a magnetic piece — silver isn’t magnetic. A magnet test catches this instantly.
• “EPNS” or “EP” — Electroplated Nickel Silver. Zero silver content. A thin silver layer over base metal.
• “Silver” with no number — meaningless. Could be silver-plated brass.
• “IS” or “IN” — Indian Silver, usually low-purity silver (50–70%). Not a standard hallmark.

I saw a seller at a craft fair offering “925 sterling silver” rings for $12 each. The stamp looked perfect. But the ring was light — suspiciously light. A quick magnet test? It stuck. The seller had bought blank base-metal rings and stamped them with a hobby die. The stamp was real. The metal wasn’t.

Platinum and Palladium Hallmarks: The Expensive Ones

Platinum and palladium are rarer than gold, denser, and more expensive. Their hallmarks are different from gold and silver.

Platinum Hallmarks

Look for 950, 900, or 850. The number indicates parts per thousand. 950 platinum is 95% pure platinum — the most common in jewelry. Platinum is about 60% denser than 14K gold. A platinum ring feels noticeably heavier than the same ring in gold.

Platinum doesn’t tarnish, doesn’t turn skin green, and holds stones securely because the metal is stiff. The downside: it costs $1,200–$1,800 per ounce (2026 prices), and resizing a platinum ring costs double what gold costs because it requires higher heat and special tools.

Palladium Hallmarks

Palladium is part of the platinum group but cheaper and lighter. Look for 950 or 500. Palladium 950 is 95% pure. It looks similar to white gold but doesn’t need rhodium plating. It’s also hypoallergenic — good for people with nickel allergies.

Palladium was $1,000–$1,400 per ounce in early 2026. That’s cheaper than platinum but still expensive. The catch: fewer jewelers work with palladium, so repairs take longer and cost more.

When to Choose Platinum Over Gold

If you’re buying a ring you’ll wear every day for decades — a wedding band or engagement ring — platinum is the better metal. It wears down slowly (gold loses mass over time), doesn’t need replating, and holds stones better. The upfront cost is higher, but the lifetime cost is lower because you won’t need to replace it.

If you’re buying fashion jewelry you’ll wear occasionally, stick with 14K gold or 925 silver. The cost difference isn’t worth it for occasional wear.

How to Spot a Fake Hallmark — 4 Tests You Can Do at Home

Fake hallmarks are common. A Chinese factory stamps “750” on a brass ring and sells it as 18K gold. The stamp looks real because the die is good. But the metal doesn’t match.

Test 1: The Magnet Test

Gold, silver, platinum, and palladium are non-magnetic. If a piece labeled “925” or “585” sticks to a magnet, it’s fake. Period. Use a neodymium magnet ($8 on Amazon) — it’s stronger than a fridge magnet and catches weakly magnetic alloys.

Test 2: The Weight Test

Gold is dense — 19.3 grams per cubic centimeter. Silver is 10.5 g/cm³. A fake piece made of brass (8.5 g/cm³) or steel (7.8 g/cm³) feels noticeably lighter. If a “gold” ring feels as light as a stainless steel ring, it’s not gold. This takes practice. Compare against a known genuine piece.

Test 3: The Mark Test

Real hallmarks are crisp, deep, and uniform. Fake stamps are often shallow, blurry, or uneven. Use a 10x jeweler’s loupe ($15 on Amazon). Look at the edges of the stamp. If they’re rounded or fuzzy, the stamp was applied after casting — a sign of fakery.

Test 4: The Acid Test (Last Resort)

Jewelers use nitric acid to test gold. You can buy a gold testing kit ($25–$40) with small bottles of acid for 10K, 14K, 18K, and 22K. You scratch the piece on a testing stone, apply the acid, and watch the reaction. If the 18K acid dissolves the mark, it’s not 18K. This test leaves a tiny scratch. Use it only if you’re serious about buying and the seller allows it.

One caveat: acid tests don’t work on plated pieces. A gold-plated brass ring will pass the 18K acid test because the surface is gold. The test only checks the surface. For plated pieces, you need a density test or an XRF scanner (professional tool, $3,000+).

When a Hallmark Isn’t Enough — and What to Do About It

A hallmark is a good sign, but it’s not a guarantee of quality. Here’s when to be skeptical.

Vintage and Antique Jewelry

Old hallmarks can be worn down, making them unreadable. That doesn’t mean the piece is fake. But it also doesn’t mean it’s real. If you’re buying a vintage piece with worn hallmarks, ask the seller for a written guarantee of metal content. Reputable dealers will provide one.

I bought a Victorian brooch stamped with a partial leopard’s head — the London assay mark. The rest of the hallmark was too worn to read. I took it to a jeweler who did an XRF test ($30). It came back as 18K gold. The worn hallmark was a good sign, not a bad one.

Hallmarks on Watches

Watch cases often have hallmarks on the outside of the case back. But many watch brands use stainless steel with a gold coating. The hallmark might say “750” on the buckle but the case is steel. Always check the case itself, not the clasp or buckle.

What to Do If You Suspect a Fake

If you bought from a retailer and suspect the hallmark is fake, contact your country’s assay office. In the UK, the Goldsmiths’ Company Assay Office investigates fake hallmarks. In the US, contact the Federal Trade Commission (FTC) — they regulate precious metal marking under the Jewelry Guides.

For online purchases, eBay and Etsy have buyer protection policies. Document the stamp with clear photos, request a refund, and escalate if the seller refuses. Most platforms side with the buyer when hallmarks are proven fake.

The single most important thing: never buy precious metal jewelry without a clear, readable hallmark from a known assay office. If the stamp is missing, blurry, or unfamiliar, assume it’s fake until proven otherwise.