How to Tell If a Gold Jewelry Piece Is High Quality?

Gold jewelry is built to last. Yet between gold-plated pieces that wear out within a few years, secondhand jewelry with no legible hallmark, and diamond certificates you're not sure what to make of, there's no shortage of uncertainty. This guide gives you the concrete tools to read a jewelry piece before you buy: the legal markings to look for, the differences between types of gold, checks you can do at home versus those that require a professional, and the specific red flags to watch for when buying secondhand…

Reading a Jewelry Hallmark Before You Buy

The first step, before any other test, is to look for hallmarks engraved on the piece. In France, the guarantee of precious metals is administered by the General Directorate of Customs (DGDDI), which operates six regional assay offices responsible for testing and marking jewelry.

The Hallmark of Guarantee: What It Certifies

The guarantee hallmark - or fineness mark - is the official stamp that certifies the proportion of gold in the alloy. It is applied to every piece of gold jewelry weighing more than 3 grams that is legally sold in France.

The legal gold standards in France are as follows:

The eagle's head is the most common hallmark in France: it identifies jewelry manufactured or guaranteed on French territory in 750 gold (18 karats). Imported jewelry carries different hallmarks, defined by an international convention.

Below 375‰, a piece of jewelry cannot legally be described as "gold" in France.

The Maker's Mark

In addition to the hallmark, each piece of jewelry carries a maker's mark - a unique identifier belonging to the manufacturer or importer, engraved in a lozenge-shaped cartouche (manufacturer) or oval (importer). This mark is traceable: in the event of a dispute, it identifies who placed the item on the market.

On a new piece of jewelry purchased from a jeweler, both hallmarks should be present. Their absence can be considered a red flag.

Where to Find the Hallmarks

They are engraved in discreet but accessible spots: the inside of a gold signet ring, the clasp of a necklace or bracelet, the setting of an earring. On finer pieces, a loupe (×10 magnification) helps to read them. Most jewelers offer this check free of charge.

Solid Gold, Gold-Plated, Vermeil: Know the Difference

These three designations coexist on the market but represent very different realities - and very different levels of durability.

• Solid gold (or "full gold"): the alloy contains the stated proportion of gold throughout its entire thickness. A piece of 750‰ (18-karat) solid gold jewelry is 75% pure gold through and through. It does not wear down, does not tarnish, and can be reworked indefinitely by a jeweler.
• Gold-plated: a base metal (brass, copper) coated with a thin layer of gold through electroplating. French regulations require a minimum thickness of 3 microns to use the label "gold-plated." This coating wears away over time - within a few months to a few years depending on how often it's worn and the wearer's skin chemistry - eventually exposing the base metal.
• Vermeil: a 925 sterling silver base coated with at least 5 microns of 750‰ gold. Higher quality than standard gold-plated jewelry, vermeil is still a gold-surface piece - not solid gold. With daily wear, it lasts one to five years; worn occasionally, it can last considerably longer.
• Gold-filled: the gold layer represents at least 1/20 of the jewelry's total weight (5%). More durable than standard gold-plated, but still distinct from solid gold.

The distinction is visible on the label and the hallmark: only solid gold carries an official guarantee hallmark. Gold-plated and vermeil items do not bear a government hallmark - their nature may be stated on the packaging, but this is not verified in the same way. A square hallmark is often a sign of gold plating.

Verifying Authenticity Without Lab Equipment

What you can do yourself

• Look for the hallmark (see previous section): this is the most reliable at-home check, provided you know how to read French hallmarks.
• Magnet test: gold is not a magnetic metal. A solid gold piece of jewelry should not be attracted to a strong magnet. This test has its limits: it rules out fakes made of iron or nickel, but won't detect non-magnetic alloys like brass or copper, which can mimic gold without being drawn to a magnet.
• Density test: 999 gold (24 karats) has a density of 19.32 g/cm³ - one of the highest among common metals. By weighing the jewelry and then measuring the volume of water it displaces in a graduated cylinder, you can calculate an approximate density. A result well below 15 g/cm³ for a piece claimed to be 750 gold (18 karats) is suspicious. This test requires a precision scale (accurate to one-tenth of a gram).
• Popular but unreliable tests (vinegar, lighter, ceramic): several methods circulate online - rubbing the jewelry on unglazed ceramic (gold leaves a golden streak, an inferior alloy leaves a black mark), exposing the jewelry to a flame (genuine gold does not blacken), or exposing it to vinegar (gold does not react, other metals tarnish). All of these tests have serious limitations: they can potentially damage the jewelry's surface, they do not distinguish between gold purities, and they produce results that are difficult to interpret without practice. They are no substitute for a hallmark or a professional test - they are mentioned here solely to caution against using them alone as proof of authenticity.

What Requires a Professional

• The acid test uses nitric acid applied to a touchstone after rubbing the jewelry against it. The reaction (or lack thereof) at a given gold karat indicates the purity of the alloy. It's the most accurate test short of lab equipment, but it involves corrosive chemicals and requires basic training. Most jewelers or gold buyers can perform it in a matter of minutes.
• XRF spectrometry analysis (X-ray fluorescence) is used by gold buying professionals and assay offices. It determines the exact composition of the alloy without altering the jewelry, in a matter of seconds.

For any piece of valuable jewelry - whether buying or selling - an appraisal by a jeweler, auctioneer, or licensed gold buyer remains the most reliable guarantee.

Jewelry with Diamonds: The Right Approach

A piece of gold jewelry set with a precious stone - like a diamond ring or a sapphire bracelet - calls for an additional check: verifying the stone itself.

The Gemological Certificate

For any diamond of significant size (from approximately 0.30 carats), always request a certificate issued by a recognized independent laboratory: GIA (Gemological Institute of America), IGI (International Gemological Institute), or HRD (Hoge Raad voor Diamant). These are the global benchmarks, and their certificates can be verified online directly on their websites.

Each certificate carries a unique number verifiable at gia.edu, igi.org, or hrd.be. Entering this number confirms that the report exists, that it matches the stone, and that it correctly identifies the nature of the stone - natural or lab-grown (GIA-certified lab-grown diamonds have carried the laser-engraved "Laboratory-Grown" inscription on the girdle since 2019).

Be cautious of in-house certificates or those issued by lesser-known laboratories (AIG, EGL Europe in particular): they do not meet the same standards of rigor and are not recognized on the international market.

Verify the Match

On a certified set jewelry piece, the report number is laser-engraved on the girdle (the edge of the stone), readable under a ×10 loupe. Matching this engraving to the certificate is the minimum verification to perform before any purchase.

How do you get a stone certified if it has no certificate?

An inherited or secondhand piece of jewelry may not come with a gemological certificate. It is possible to have the stone certified after the fact by sending it directly to a recognized laboratory (GIA, IGI). The process generally requires removing the stone - which must be done by a jeweler. Budget between 80 and 150 € depending on the stone's size and the laboratory chosen, plus the jeweler's fees for setting and resetting. This step is worthwhile whenever the estimated value of the stone exceeds a few hundred euros.

Secondhand Purchases: Extra Vigilance Required

Buying secondhand gold jewelry - whether from a private seller, flea market, auction, or online platform - offers real opportunities but requires extra caution.

Check the hallmark first: this is even more important than with a new piece of jewelry, since the seller's guarantee is absent or limited. A French piece from the 20th century will carry the hallmarks described above. Antique jewelry (pre-1838 or imported from a specific period) may carry different hallmarks or none at all - which does not necessarily mean the piece is not gold, but does require a professional appraisal.

Always ask for an invoice or receipt: even in a private sale, a document tracing the jewelry's origin holds value in the event of a dispute.

Be wary of sellers who refuse any prior appraisal: a seller acting in good faith has no reason to object.

For jewelry with gemstones: as with gemstone rings, the absence of a certificate is not a dealbreaker on an antique piece, but it requires an independent gemological appraisal before purchase. The cost of an appraisal (30 to 80 € depending on the piece) is well worth it whenever the amount at stake exceeds a few hundred euros.

Auctioneers and licensed auction houses: for higher-value jewelry, going through a supervised auction offers stronger guarantees than a private sale. The appointed experts are legally required to identify metals and gemstones.

Summary Table

Frequently Asked Questions

Does unmarked jewelry always mean a fake?

Not necessarily. Very old jewelry (predating 19th-century hallmarking reforms), certain handcrafted pieces, or foreign items from specific periods may not carry a French hallmark. However, a recent piece sold as "750 gold" with no readable hallmark must be professionally appraised before purchase.

Can gold-plated jewelry carry the label "gold"?

No. In France, regulations prohibit using the word "gold" alone to describe a gold-plated piece of jewelry. The label must be explicit: "gold-plated," "gilded," or "rolled gold." The term "gold" without further qualification legally refers to solid gold.

How do you tell white gold from silver or platinum?

White gold is rhodium-plated at the surface - its tone is slightly warmer than platinum or silver (though rhodium-plated silver jewelry does exist). Under a loupe, the hallmark is the deciding factor: eagle's head for 750 white gold (18 karats), a specific hallmark for platinum, and a different one for silver. When in doubt, a professional XRF test provides a definitive answer.

Can you have an inherited piece of jewelry appraised before selling it?

Yes - and it's actually recommended. A jeweler, auctioneer, or licensed gold buyer can carry out a quick appraisal (often free when it precedes a purchase offer). For valuable pieces, an independent gemological appraisal is preferable to one performed by the potential buyer.

Shop Our Certified Gold Jewelry

Every piece of gold jewelry offered by Ocarat is guaranteed to meet French legal standards - solid hallmarked 750 gold (18 karats) or 375 gold (9 karats), accompanied by a detailed invoice. Jewelry set with a diamond over 0.3 carats is GIA or IGI certified. Free delivery in mainland France and Belgium, 4-installment payment with no fees, 30 days to change your mind.

See Also

→ Your first gold jewelry purchase - how to choose? · Guide to Precious Metals · Natural vs. Lab-Grown Diamond - How to Choose?

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