What Do Jewelry Hallmarks Mean? A Complete Guide to Gold, Silver & Platinum Stamps

When buying or examining luxury jewelry, you’ll often notice tiny markings stamped into the metal. These are known as jewelry hallmarks , and they serve as an essential key to understanding the item’s true value.

To help you understand these important stamps—and distinguish which metals are fine, pure, and worth their higher price tags—we’ve put together a detailed guide outlining the most frequently used hallmarks in jewelry . Whether you’re a seasoned collector, a first-time buyer, or someone exploring the world of vintage and pre-owned pieces, knowing how to read these marks can significantly enhance your shopping experience.

For those exploring the market for used luxury jewelry, understanding hallmarks jewelry is especially crucial. These tiny engravings not only verify the authenticity of the piece but also provide valuable insight into its metal purity, origin, and craftsmanship. Whether you’re considering a pre-owned diamond necklace from Cartier or a vintage platinum ring, hallmarks act as a roadmap to ensure you’re investing in genuine, high-quality workmanship.

Used luxury jewelry often carries the allure of timeless design and historical significance, making it a sustainable and sophisticated choice for collectors and gift-givers alike. But without proper identification through hallmarking, even the most beautiful piece could be difficult to authenticate or assess accurately.

What Is the Difference Between Carat and Karat?

Before diving into the specifics of hallmarks, it’s important to clarify two terms that are often confused: carat and karat .

Carat

A carat refers to the weight of a stone and is commonly used to describe diamonds or gemstones. One carat equals 200 milligrams. This measurement helps determine the size and, often, the value of the stone in question.

Karat

On the other hand, a karat is a unit used to measure the purity of gold. Gold in its purest form—known as 24 karat (24K) gold —is too soft for everyday wear, so jewelers typically mix it with other metals like silver, copper, or zinc to create durable alloys.

As a result, gold jewelry is usually labeled based on its gold-to-alloy ratio . For example:

• 18 karat gold means 18 parts gold and 6 parts alloy (75% pure gold).
• 14 karat gold means 14 parts gold and 10 parts alloy (58.3% pure gold).

These numbers, particularly the karat values, are critical when evaluating a piece for authenticity and determining its specifications. On most quality jewelry, you’ll find these details engraved as a hallmark—often located on the inside of a ring band, the clasp of a necklace, or the back of a pendant.

Hallmarks essentially act as a certification of the precious metal’s fineness and purity, helping buyers make informed decisions.

Common Gold Jewelry Hallmarks

Pure gold is 24 karats and is typically stamped as 999 to reflect its near-perfect purity (99.9% gold). As we move down the scale of gold purity, the hallmark numbers change accordingly.

Gold hallmarks are expressed in either karatage (e.g., 18K and 14K Gold) or millesimal fineness (e.g., 750 for 18K gold), depending on the country of origin or the manufacturer’s preference.

Here’s a breakdown of the most common gold hallmarks and what they mean:

Understanding gold hallmarks on rings or other items will help you quickly identify whether a piece is made of solid gold or gold-plated material. It’s also helpful when comparing the value of different gold items, especially when shopping second-hand.

Common Platinum Jewelry Hallmarks

Like gold, platinum is measured by its fineness—but unlike gold, it is not measured in karats. Instead, platinum is evaluated by its purity percentage , and hallmarks reflect this.

The highest standard for platinum jewelry is 95% pure platinum , which is marked as Pt950 . Other common platinum hallmarks include:

Platinum is highly valued for its durability, rarity, and natural white sheen, which does not fade or tarnish over time. Because of its value, counterfeit platinum jewelry is not uncommon—making hallmark verification all the more essential.

If you come across a piece marked as “Platinum” but there’s no numerical stamp like Pt950 , proceed with caution. Always look for both the word “Platinum” and a millesimal number to confirm authenticity.

Common Silver Jewelry Hallmarks

While pure silver exists, most silver jewelry sold today is made from sterling silver , an alloy composed of 92.5% pure silver and 7.5% other metals (usually copper). This blend enhances the metal’s strength and makes it suitable for crafting jewelry.

This is where the famous 925 hallmark comes into play. The 925 stamp on jewelry indicates that the piece is made of sterling silver. It is one of the most recognizable silver hallmarks, especially among brands like Tiffany & Co., who have long used the 925 hallmark as part of their authentication process.

In fact, if you’re looking at a piece of jewelry claiming to be from Tiffany & Co. and it doesn’t have the 925 stamp , it may not be authentic. So always double-check for this hallmark when verifying Tiffany jewelry.

Other common silver hallmarks include:

Silver hallmarks are especially useful when shopping for vintage silver pieces, such as antique brooches or heirloom necklaces. They help identify not just the purity of the metal, but also the era and origin of the piece.

Where Are Hallmarks Typically Located on Jewelry?

Jewelry hallmarks are usually found in discreet locations on the piece, depending on the type of jewelry:

• Rings: Inside the band
• Necklaces/Chains: On the clasp or a small pendant link
• Earrings: On the post or back of the earring
• Bracelets: On the clasp or inner side of the bangle

Use a magnifying loupe or jeweler’s glass to better see small engravings. Some hallmarks may be faint, especially on older or well-worn pieces.

How to Verify If a Hallmark Is Real or Fake

Not all hallmarks are genuine. Here’s how to tell if a hallmark might be fake:

• Mismatched font or size : Authentic hallmarks are usually uniform and clean.
• Hallmark not matching brand style : Compare against official brand guides (e.g., Tiffany hallmark vs. Cartier hallmark).
• Missing secondary marks : Many brands also include serial numbers or designer marks alongside purity stamps.
• Use professional testing : Acid tests, electronic testers, or consulting an appraiser can confirm metal type and authenticity.

If you’re ever unsure about a hallmark, consider consulting a professional appraiser or jeweler who specializes in vintage or luxury pieces.

Final Thoughts

Understanding jewelry hallmarks empowers you to make smarter, more confident purchasing decisions—especially when dealing with secondhand or vintage pieces. From gold hallmarks on rings to the 925 stamp on jewelry , each marking tells a story about the piece’s composition, origin, and authenticity.

Whether you’re browsing QVC jewelry hallmarks , exploring a list of jewelry hallmarks , or decoding Tiffany jewelry hallmarks , taking the time to learn these symbols will elevate your appreciation for fine jewelry and protect your investment.

So next time you pick up a vintage locket or a pre-owned bracelet, don’t forget to flip it over and check the hallmarks—they might just reveal the hidden history behind the piece.