Jewellery Hallmarks Explained: What 750, 585 and Other Stamps Mean

Hallmarks and stamps in jewellery making serve as permanent records of a piece’s metal purity, origin, and authenticity. These tiny markings—often overlooked by the untrained eye—are key to understanding the value and story behind your jewellery. Whether you’re buying new, restoring a family heirloom, or getting a piece valued, knowing how to read gold hallmarks and interpret gold stamps can make all the difference. In this article, we’ll explain what they mean, what the most common gold number codes are, and how to spot antique gold hallmarks that could increase a piece’s worth or historical importance.

Key Takeaways – Summary

• Hallmarks and stamps confirm the precious metal’s purity and authenticity
• A 750 gold stamp means 18ct gold; 585 gold stamp means 14ct gold
• Antique gold hallmarks can help determine age, maker, and origin
• Each country uses different gold hallmark symbols
• No hallmark doesn’t always mean fake—but it does require further testing
• A trusted jeweller can help interpret worn or unclear markings
• Hallmarking exists for more than just gold—silver and platinum are also included

What Are Hallmarks and Stamps?

The Basics

Hallmarks and stamps are small marks applied to jewellery and precious metal items to certify their purity and composition. While the terms are often used interchangeably, there is a technical difference. A hallmark is applied by an official assay office, often under a government-regulated system. A stamp, on the other hand, can be applied by the manufacturer or jeweller and may not be officially certified.

What They Represent

These marks may include:

• Metal purity
• Manufacturer’s or jeweller’s mark
• Assay office symbol
• Year of production
• Country of origin

They provide assurance for buyers and help jewellers or valuers identify the material and potentially the item’s history.

Why Hallmarks Matter

Peace of Mind and Trust

For both customers and jewellers, hallmarks and stamps are a point of reference. They provide reliable information on the metal content—especially important for pieces made from high-value materials like gold. When you’re dealing with 18ct or 14ct jewellery, knowing what the gold stamp says allows you to verify what you’re paying for or inheriting.

Legal and Trade Requirements

In countries like the UK and Australia, hallmarking of certain precious metals is required by law for retail sale. Even when not legally required, jewellers often stamp their items to provide clarity and build trust with customers.

Understanding Gold Hallmark Symbols

The Main Components

Each gold hallmark includes a combination of elements:

1. Purity Mark (e.g., 750 or 585)
2. Maker’s Mark
3. Assay Office Mark (in some countries)
4. Additional Marks (like year letter codes)

Gold Hallmarks in Australia

In Australia, there isn’t a central assay office, so hallmarking is less standardised than in countries like the UK. However, most jewellers still apply stamps to indicate gold content, often following international standards. It’s common to see purity stamps like 375, 585, 750, or 916.

What the Gold Number Codes Mean

The 750 Gold Stamp

The 750 gold stamp means the item is 18ct gold—comprising 75% pure gold and 25% alloy for strength. This is one of the most common gold stamps used in high-quality jewellery.

The 585 Gold Stamp

A 585 gold stamp indicates 14ct gold—58.5% pure gold and 41.5% alloy. It’s popular in many countries, offering a balance between durability and gold content.

Other Common Codes

These gold number codes are often accompanied by additional gold hallmark symbols that show the manufacturer or country of origin.

Antique Gold Hallmarks

Telling a Story Through Stamps

Antique gold hallmarks offer more than just a confirmation of purity. They provide insight into the history and craftsmanship of older pieces. You might find unique symbols no longer in use today—such as specific letters, shield shapes, or animals that indicate city and year of origin.

Examples and Interpretation

• A lion symbol often indicates sterling silver in British hallmarking, but antique gold hallmarks can include different crown shapes or regional symbols.
• A piece with a 750 gold stamp from the early 1900s may still be wearable, but the design and materials used at the time give it additional collectible value.

If you’re unsure of the markings, a jeweller experienced in antique restorations can assist in interpreting faded or unusual symbols.

Hallmarking Systems by Country

Variations You Should Know

Different countries use different hallmarking systems. For example:

• UK: Mandatory hallmarking by government assay offices
• USA: Stamps are applied by manufacturers, not official bodies
• Europe: Uses numeric purity codes and country marks
• India: BIS hallmarking (Bureau of Indian Standards)
• Australia: Voluntary but follows European norms

This can affect the marks you see on imported or vintage jewellery.

What If There’s No Hallmark?

Not Always a Red Flag

Some jewellery, especially handmade or vintage pieces, may not have a hallmark due to various reasons—such as wear over time, informal production, or being made before hallmarking became standard. This doesn’t necessarily mean the item is fake.

When to Test

If there’s no visible stamp or if it looks suspicious, it’s best to get the piece tested professionally. At Gillian’s Jewellery, we perform metal testing to verify the gold content—even if a stamp is missing or worn down.

How to Spot Fake or Forged Hallmarks

Red Flags

Unfortunately, fake gold stamps and misleading marks do exist—particularly in second-hand markets or online sales. Be cautious of:

• Stamps that are uneven or misspelt
• Inconsistent wear between the stamp and the rest of the piece
• Cheap jewellery advertised with high-karat stamps

What to Do

If in doubt, don’t take chances. Bring the item to a trusted jeweller. We’ve seen all kinds of questionable pieces and can quickly assess their authenticity.

Hallmarks Beyond Gold

Other Metals Also Carry Stamps

Hallmarking isn’t just limited to gold. Precious metals like silver, platinum, and palladium also use hallmark systems.

• Sterling silver is usually marked 925
• Platinum often shows 950
• Palladium may carry 950 or 999

While the symbols and numbers vary, the idea remains the same—guaranteeing metal content and helping prevent fraud.

How Gillian’s Jewellery Can Help

At Gillian’s Jewellery, we’ve spent decades helping our customers understand what their jewellery truly is. Whether it’s identifying antique gold hallmarks, verifying a 585 gold stamp, or confirming whether that old ring is 18ct or not, we’re here to help.

We also specialise in restorations, remodelling, and repairs—where knowing the gold number code or hallmark is critical before we start work. If a piece doesn’t have a stamp, we’ll test it before doing anything, to ensure your jewellery is treated with the right care.

Curious About What Your Jewellery Is Made Of? Come See Us in Store

Bring your jewellery to Gillian’s Jewellery and let us help you decode what’s stamped on your pieces. Whether you’re trying to verify a 750 gold stamp, identify antique gold hallmarks, or just want to know the gold number code before you remodel, we’ll walk you through it.

We’d love to help you uncover what makes your jewellery truly valuable—beyond what meets the eye.