Understanding Designer Jewelry Hallmarks and Signatures

Designer jewelry is more than just an accessory—it’s a work of art, a statement of luxury and oftentimes a valuable investment. Whether you’re a collector or you just love things that sparkle, understanding hallmarks and signatures is essential for identifying and authenticating high-quality pieces. These tiny marks, often hidden on the clasp or underside of a piece, provide crucial information for designer jewelry authentication. Here’s how to separate the real from the fake when shopping high-end jewelry.

What Are Hallmarks and Signatures?

Hallmarks and signatures are essential identifiers in the world of designer jewelry, serving as the ultimate proof of authenticity and quality. These small but significant marks provide vital information about a piece’s composition, making them indispensable tools for determining the rarity and material of your jewelry.

What’s a hallmark in the first place? Hallmarks are official stamps or engravings that indicate the type and purity of the metal used in a piece of jewelry. For example:

• Metal purity marks: These include numbers like “925” (sterling silver), “585” (14k gold) or “950” (platinum). These marks verify the composition of the metal and verifies that it meets specific quality standards.
• Assay office marks: Some countries like the United Kingdom use additional marks to indicate where the metal was tested and certified for purity. These are called assay office hallmarks.
• Maker’s marks: These unique symbols or initials identify the jeweler, workshop or company that crafted the piece, adding a personal touch to its history.

Similar to hallmarks are designer jewelry signatures, which are unique engravings or markings that identify the designer or brand behind the jewelry. These marks not only confirm authenticity but also connect the piece to the prestige and reputation of its creator. Many luxury brands like Cartier and Tiffany & Co. engrave their name or logo on their pieces. The placement, font and style of these signatures are kept consistent and recognizable between pieces and batches. Sloppy signatures can be one of your most useful tools in identifying replicas and fakes.

Types of Hallmarks and Signatures

Understanding the various types of jewelry hallmarks and their significance is essential for anyone navigating the world of luxury jewelry. Here are the most common types you’ll encounter and how to verify them visually.

Metal Purity Marks

These marks indicate the precious metal content in a piece of jewelry. Examples include:

• “925” for sterling silver, denoting 92.5% pure silver
• “585” for 14k gold, representing 58.5% pure gold
• “750” for 18k gold, indicating 75% pure gold
• “950” for platinum, meaning 95% pure platinum

Search for clean, precise engravings; they’re usually located on clasps, inner bands of rings or the back of pendants.

Assay Office Marks

These marks certify that the jewelry’s metal content has been tested and verified by an official assay office. The two most common assay office hallmarks you’ll see are those used by the United Kingdom and France. Depending on the piece’s country of origin, you’ll need to look for:

• UK hallmarking system: Includes a lion for sterling silver, a crown for gold or a leopard’s head for London assay office
• French hallmarks: Often feature an eagle’s head for gold or a Minerva’s head for platinum

The most common red flag among assay office markings are marks that don’t correspond to the claimed country of origin. For example, real pieces from Van Cleef & Arpels use an eagle mark to certify the gold purity of their pieces crafted in France. Be wary of symbols that appear incomplete or poorly stamped, but remember that assay marks are not required in all countries.

Maker’s Marks

It’s more than your favorite whiskey—maker’s marks are crucial tools used to authenticate luxury jewelry. Maker’s marks are often small stamps or engravings that denote the workshop, jeweler or company responsible for crafting the item. As the name suggests, these markings vary by brand, which can sometimes make them more challenging to identify. The key is to research authentic brand hallmarks online and compare them to the piece that you’re considering for purchase.

For example, the Cartier Love bracelet includes the Cartier name, a serial number and most often “750” to indicate that the piece is made from 18k gold. Each piece includes the signature “Cartier” engraved in elegant, consistent script, often accompanied by a unique serial number. On the other hand, a Return to Tiffany necklace should feature “Tiffany & Co.” stamped in a clean, bold font on the necklace’s clasp or on the underside of the pendant. A Tiffany engagement ring might read “Tiffany & Co. PT950” (for platinum), with higher end metals denoted alongside the signature.

Brand Signatures

Luxury brands engrave their names or logos on designer pieces to indicate authenticity. With a magnifying glass and knowledge of brand-specific engraving styles, you can verify the authenticity of each piece based on the placement and cleanliness of the engraving. For example, a genuine Van Cleef & Arpels Alhambra pendant necklace should feature a small oblong tag close to the tag bearing the company’s signature. Pass on pieces with misspellings, uneven or sloppy engravings or fonts that vary from the ones you see on authentic items.

How to Identify Authentic Hallmarks and Signatures

To verify the authenticity of high-end jewelry, you’ll need to gather some specific tools. A 10x magnification jeweler’s loupe is essential for inspecting small and intricate markings, while smartphone cameras with macro settings can also help capture and enlarge marks for closer inspection. Look for clean, sharp edges and precise engraving. Remember to use bright, even lighting to illuminate the piece—shadows can obscure the fine details of the marks, making your job harder.

Use books or online resources to compare hallmarks against documented examples. For example, the UK Assay Office maintains databases of official assay marks used throughout time, complete with video verification examples. For common pieces, designer websites can be indispensable resources to find where engravings should be located on each item.

Shop Authentic Pre-Loved Jewelry

The RealReal employs a full team of authentication experts who carefully inspect each piece listed for sale. Even with the rise of “superfakes,” you can sleep easy when you shop The RealReal—our team seized more than 5,000 replica items in 2024 alone, removing them from the market.

Find your next fine jewelry investment now.