A tiny stamp inside a ring or on the back of a piece of jewelry can tell you a lot. But it can also be surprisingly easy to misread.

You might see:

14K
14KT
14K RGP
14KT GP
14K GF
585

At first glance, they all seem to contain the words “14K.”

But they do not necessarily mean the same thing.

The most important rule is simple:

Do not stop reading after “14K” or “14KT.” Read the entire stamp.

What Does 14K Mean?

Pure gold is 24 karat.

14K gold contains approximately 58.5% pure gold, with the remaining portion made from other metals.

That is why 14K jewelry may also be marked:

585

You may also see:

14K
or
14KT

K and KT are both commonly used as abbreviations for karat.

So by themselves, 14K and 14KT generally refer to 14-karat gold.

But there is an important catch.

Seeing “14KT” Does Not Automatically Mean the Whole Piece Is 14K Gold

This is where jewelry markings can get confusing.

You may also see 14K or 14KT as part of a longer marking on jewelry that has a layer of 14K gold over another metal.

For example:

14KT RGP
14KT GP
14K GEP

In those cases, the 14KT portion is describing the gold used in the outer layer.

It does not necessarily mean the entire piece is made from 14K gold alloy.

Jeweler’s Note

This is exactly why I always look at the complete marking.

I have seen jewelry where 14KT appears prominently in the stamp, but the piece was plated rather than solid 14K gold.

If you only notice the “14KT” and ignore the letters beside it, it is very easy to misunderstand what the piece actually is.

What Does RGP Mean?

RGP stands for Rolled Gold Plate.

Rolled gold plate is made by mechanically bonding a layer of gold alloy to another metal.

So a stamp such as:

14K RGP

does not mean that the entire piece is 14K gold.

The 14K describes the gold alloy used in the outer layer.

The RGP tells you that this gold exists as a bonded layer over another metal.

That makes:

14K

and

14K RGP

two very different descriptions.

What Does GP Mean?

GP generally means Gold Plated.

A piece marked:

14K GP
or
14KT GP

has a layer of 14K gold over another metal.

Again, the karat number refers to the gold used in the plating.

It does not mean the entire piece is 14K gold.

What Does GEP Mean?

GEP means Gold Electroplated or Gold Electroplate.

This refers to a gold layer applied using an electroplating process.

You may see something like:

14K GEP

The presence of 14K still does not make the underlying piece solid 14K gold.

The additional letters matter.

What Does GF Mean?

GF means Gold Filled.

The name is slightly misleading because the jewelry is not literally “filled” with gold.

Gold-filled jewelry typically has a relatively substantial layer of gold alloy mechanically bonded to a base-metal core.

A marking may look something like:

1/20 14K GF

The additional numbers and letters describe the gold layer and its relationship to the rest of the article.

Gold-filled jewelry is different from ordinary gold plating, but it is also different from a piece made entirely from 14K gold alloy.

What Does 585 Mean?

585 is another common way of identifying 14K gold.

The number refers to gold fineness:

585 = approximately 58.5% pure gold

Likewise:

750 = 75% pure gold = 18K

These numerical marks are especially common on jewelry made outside the United States.

Is “Solid 14K Gold” Pure Gold?

No.

This wording creates another common misunderstanding.

Solid 14K gold is not 100% pure gold.

It still contains approximately 58.5% pure gold.

In jewelry, the word solid is generally used to distinguish a piece made from a gold alloy throughout from a base-metal piece that only has a gold layer on the surface.

So:

Solid 14K gold ≠ pure gold

It means the piece itself is made from 14K gold alloy rather than simply being coated with it.

Quick Guide to Common Gold Marks

Mark	General Meaning
14K	14-karat gold
14KT	14-karat gold
585	Approximately 58.5% gold
18K / 18KT	18-karat gold
750	Approximately 75% gold
RGP	Rolled Gold Plate
GP	Gold Plated
GEP	Gold Electroplated
GF	Gold Filled

But remember:

The complete stamp matters more than any single part of it.

14KT

and

14KT GP

should not be read as the same thing.

Why Does This Matter?

Knowing how to read a jewelry stamp can affect how you understand:

• what the piece is made from
• its gold content
• its potential resale or scrap value
• how it may wear over time
• whether certain repairs are practical
• how the piece should be accurately described

This can be particularly useful when looking at vintage jewelry, inherited pieces, secondhand jewelry, or pieces whose original paperwork is no longer available.

The Simplest Rule

When you see a jewelry stamp, read every letter and number.

Do not see 14K or 14KT and immediately assume the entire piece is made from 14K gold.

Look for anything that comes after it:

RGP
GP
GEP
GF

Those small letters can completely change the meaning of the mark.

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Jewelry Field Notes

Jewelry Field Notes explores jewelry materials, construction, gemstones, techniques, terminology, and practical industry knowledge from the perspective of a working jeweler.