Jewelry Hallmarks Guide

Jewelry often contains small stamped markings called hallmarks that indicate the metal type and purity. Learning how to read these marks can help you determine whether your jewelry is made from gold, silver, or platinum, and give you a better idea of its value.

At Red Bluff Gold Exchange, we frequently help customers identify jewelry metals and purity marks. Below is a quick guide to some of the most common jewelry hallmarks.

Common Gold Purity Marks

Gold jewelry is often stamped with numbers that represent its gold purity. These numbers correspond to the karat value.

Stamp	Gold Purity
417	10K Gold
585	14K Gold
750	18K Gold
950	22K Gold

The letter “K” stands for karat, which indicates the purity of gold in the jewelry.

Older British Gold Marks

Jewelry produced in Britain between the 1700s and 1975 often includes:

• A crown symbol representing gold
• A number followed by “c” or “ct.” indicating the karat weight

Sterling Silver Hallmarks

Sterling silver jewelry is most commonly stamped:

925

This means the piece contains 92.5% pure silver, which is the standard for sterling silver.

Traditional British sterling silver may also feature a walking lion symbol, which is another hallmark for sterling silver.

Platinum Purity Marks

Platinum jewelry typically includes one of the following purity stamps:

• 850
• 900
• 950
• 999

You may also see “Pt”, which is the abbreviation used to identify platinum jewelry.

Gold-Filled and Vermeil Jewelry

Some jewelry contains gold but is not solid gold.

Vermeil

Refers to gold plating over sterling silver.

Gold-Filled Jewelry

Gold-filled pieces contain a thicker layer of gold bonded to base metal. These are often marked with:

• 10K GF
• 12K GF
• 14K GF

The letters GF stand for Gold Filled.

Common Gold Plating Marks

Plated jewelry contains only a thin layer of gold over base metal. Some common stamps include:

Mark	Meaning
GP	Gold Plate
GEP	Gold Electroplate
RGP	Rolled Gold Plate (thicker plating, often seen on antique jewelry)
1/20	Indicates the fraction of gold plating used

 

**Quick Tip: Magnet Test

Gold, silver, and platinum are not magnetic.

If a piece of jewelry strongly sticks to a magnet, it is likely not solid precious metal. However, a magnet test alone cannot fully confirm authenticity.