Is 750 the same as 18k?

Yes. 750 is the millesimal form — parts per thousand — and 18k, 18kt and 18ct are the karat form of the same standard. Continental European and modern British pieces tend to carry the number; older British and American pieces more often carry the karat mark.

How can I tell if an 18k stamp is genuine?

Read the whole stamp under a loupe first, because 18K GP, GF, HGE and RGP all mean plated or filled. Then check the wear points for pink, orange or white metal showing through, weigh the piece against its size since gold is extraordinarily dense, and try a strong magnet. For certainty, a jeweller's acid test or an XRF scan takes a minute and costs very little.

Which is better, 18k or 14k?

Neither, and it depends on use. 18 karat has more gold, a richer colour and better corrosion resistance; 14 karat is harder and more resistant to scratching and bending, which suits a ring worn daily and knocked about. Most of Europe favours 18, the United States favours 14, and both are entirely legitimate.

Is 750 gold worth more than 585?

Yes, by gold content — 75 percent against 58.5 percent, so roughly 28 percent more gold per gram. Whether a particular piece is worth more depends on weight, maker and design as well, and a heavy 14 karat piece easily outvalues a light 18 karat one.

What does 18K GP mean?

Gold plated: a thin electrodeposited layer of 18 karat gold over base metal, usually brass. It is a legally honest mark and it means the piece is not solid gold. GEP, HGE and RGP are variations on the same idea, and all have essentially no scrap value.

Lovenhall Ring

What Does 750 Mean on Jewellery?

18 karat gold: 75% gold, 25% other metals. The standard for fine jewellery in most of the world.

The millesimal mark for 18 karat gold, used worldwide7 checks

750 means the alloy is 75 percent gold by weight — eighteen parts in twenty-four, which is why it is also stamped 18k, 18kt or 18ct. The remaining quarter is copper, silver, palladium, nickel or zinc in proportions that determine the colour: more copper gives rose, more silver and palladium gives white, a balance gives yellow.

It is the standard for serious jewellery across most of Europe and Asia, and it sits at a genuine optimum. Higher gold content is softer and wears faster; lower is harder but paler and less resistant to corrosion. Eighteen karat holds a stone securely, keeps a rich colour and lasts generations.

The stamp's reliability depends entirely on where the piece was made. A British 750 mark sits beside an assay office mark applied by an independent body under a statutory system, which is a real guarantee. An unmarked-origin 750 on a piece bought online is a manufacturer's claim, and gold-plated brass stamped 750 is common enough that the claim needs checking.

The mark, decoded

The karat scale, and what each mark means

Karat is a fraction of twenty-four, and millesimal fineness is the same thing expressed as parts per thousand. Learning the pairs makes almost any gold mark readable at a glance, and it also makes an implausible mark obvious.

Note that the numbers are conventionally rounded. 14 karat is exactly 58.33 percent and is stamped 585; 22 karat is 91.67 percent and is stamped 916 or 917. A mark of 583 rather than 585 usually indicates older Soviet or Middle Eastern manufacture rather than anything wrong.

At a glance

Karat	Millesimal	Gold content	Where it is usual
24k	999 / 9999	99.9%	Bullion; jewellery in parts of Asia
22k	916 / 917	91.6%	India, the Middle East, traditional wedding gold
21k	875	87.5%	The Gulf states
18k	750	75.0%	Europe, fine jewellery worldwide
14k	585 / 583	58.5%	The United States, Germany, eastern Europe
10k	417	41.7%	The United States — the legal minimum to call it gold
9k	375	37.5%	The United Kingdom, Australia
8k	333	33.3%	Germany — below the UK legal minimum

In the United States nothing below 10 karat may be called gold. In the United Kingdom the minimum standard is 9 carat, so an 8k or 333 piece cannot lawfully be described as gold there.

The checks

Does the metal agree with the mark?

A stamp is a claim, not a property. These are ordered by how much each one settles about the metal underneath — and the first two need nothing but a loupe and good light.

01Decisive

Look for an assay office mark beside the number

This is the difference between a guarantee and a claim. In the United Kingdom, hallmarking is compulsory by law above small weight thresholds, and a genuine British mark includes a sponsor's mark, the fineness mark, and an assay office mark — a leopard's head for London, an anchor for Birmingham, a rose for Sheffield, a castle for Edinburgh. Those were applied by an independent body that tested the metal. A bare 750 with no assay mark is the maker's word.

02Decisive

Check the wear points for a colour change

Gold plating over brass is thin, and it goes first where the piece rubs: the underside of a ring shank, the edges of a clasp, the high points of a textured surface. Look for a pinker, more orange, or grey-white metal showing through. Solid gold wears to gold. This is the most reliable non-destructive check there is on a worn piece.

03Decisive

Read the stamp for qualifiers

The most effective gold fraud is not a false number but a true number with a suffix. 18K GP means gold plated. 18K GF means gold filled. 18K HGE means heavy gold electroplate. 18K RGP means rolled gold plate. Every one of those is a thin layer over base metal, and every one of them is legally honest. The letters are often tiny and worn. Use a loupe on the full stamp before believing the number.

04Decisive

Have it acid or XRF tested

A jeweller's acid test takes a minute and costs almost nothing: a tiny scratch on an inconspicuous spot, a drop of graded acid, and the reaction reads the karat. XRF is non-destructive and reads the whole composition, including whether a plated layer is masking base metal. For anything worth more than a modest sum this is the answer, and refusing a seller's objection to it is reasonable.

05Strong

Weigh it against its size

Gold is extraordinarily dense — 19.3 for pure gold, and 18 karat comes in around 15.5 depending on the alloy, against brass at about 8.5. A solid gold ring feels startlingly heavy for its size, and this is the check experienced dealers run first, before they look at anything. A piece that feels light for its bulk is hollow, plated or both.

06Strong

Try a strong magnet

Gold is not magnetic in any of its alloys. A neodymium magnet should produce nothing. Attraction means a ferrous core and settles it at once. As with silver, the reverse does not hold — brass and bronze are not magnetic either — so this test only rules out steel.

07Supporting

Look at whether the stamp sits right

On genuine work the mark is usually crisp, level and placed where convention puts it — inside a ring shank, on a clasp tongue, on the back of a pendant bail. Counterfeit stamps are often shallow, tilted, doubled where the punch bounced, oddly placed, or set in an area that has clearly been soldered afterwards. This is suggestive rather than conclusive, since old genuine marks wear soft and new fakes can be crisp.

Where the mark misleads

How a 750 mark is misread, and how it is faked

Gold's value per gram makes the fraud worthwhile in a way silver's does not, and the industry reflects that. At the crude end, plated brass stamped 750 or 18K. In the middle, the qualifier trick — a genuine 18K GP or 18K GF stamp on plated goods, relying on the buyer reading only the number. At the sophisticated end, tungsten-cored bars and heavily gold-clad pieces that pass a weight check because tungsten's density is close to gold's.

For jewellery specifically, the qualifier trick is the one to internalise, because it is entirely legal and extremely effective. GP, GF, HGE, RGP, EP and 'over' are all doing precise work in a stamp, and all of them mean the gold is a coating.

There is also under-karating, which is subtler: a piece genuinely made of gold but at a lower fineness than stamped — 14 karat sold as 18. Nothing visual detects this, and it is the specific reason assay systems exist.

The marks and signs to catch first

18K GP, GEP, HGE, RGP or EP: plated, and the stamp says so.
18K GF or 1/20 18K: gold filled — a bonded layer, not solid.
'18K over sterling' or '18K over brass': the base is what follows 'over'.
Wear points showing pink, orange or white metal: plated.
Too light for its size: hollow or base metal.
A magnet pulls it: ferrous core.
A crisp modern stamp on a piece with heavy antique wear: restamped.
A stamp on an area that has obviously been soldered: transplanted from another piece.

The variants

The forms this mark takes

Each of these is checked differently. The ones with their own page have enough that is specific to them to be worth reading separately.

18K White Gold

18 karat gold alloyed white with palladium or nickel, and nearly always rhodium plated.

Read the checks

18K Rose Gold

The same 75% gold, with copper in the balance. Harder than yellow, and it does not fade.

Read the checks

18K GF (Gold Filled)

A bonded layer of real 18k over base metal, far thicker than plating and far less than solid.

Read the checks

The market

What a 750 piece is actually worth

Metal value first, because it is the floor and it is easy to calculate. Anything worth more than melt is worth it for the maker, the age or the design — never for the stamp.

Ranges by line

What you have	What the metal is worth	Note
An 18k ring, 4 g	3 g of fine gold at spot, less margin	Multiply weight by 0.75
An 18k chain, 15 g	11.25 g of fine gold	Refiners pay a discount to spot
18K GP or HGE	Nothing	Plating is not recoverable
1/20 18K GF, 10 g	Notionally 0.375 g of gold	Not economically recoverable
A signed piece by a known house	Well above melt	Maker and design carry it

Solid gold has a floor that plated goods do not: melt value. Work out weight times fineness times spot, expect a refiner to pay somewhat under that, and treat anything above it as the value of the design rather than the metal.

Questions we are asked

What does 750 mean on jewellery?: That the alloy is 75 percent gold by weight, which is 18 karat — eighteen parts gold in twenty-four. The remaining quarter is copper, silver, palladium, nickel or zinc, and the mix determines whether the gold reads yellow, white or rose.
Is 750 the same as 18k?: Yes. 750 is the millesimal form — parts per thousand — and 18k, 18kt and 18ct are the karat form of the same standard. Continental European and modern British pieces tend to carry the number; older British and American pieces more often carry the karat mark.
How can I tell if an 18k stamp is genuine?: Read the whole stamp under a loupe first, because 18K GP, GF, HGE and RGP all mean plated or filled. Then check the wear points for pink, orange or white metal showing through, weigh the piece against its size since gold is extraordinarily dense, and try a strong magnet. For certainty, a jeweller's acid test or an XRF scan takes a minute and costs very little.
Which is better, 18k or 14k?: Neither, and it depends on use. 18 karat has more gold, a richer colour and better corrosion resistance; 14 karat is harder and more resistant to scratching and bending, which suits a ring worn daily and knocked about. Most of Europe favours 18, the United States favours 14, and both are entirely legitimate.
Is 750 gold worth more than 585?: Yes, by gold content — 75 percent against 58.5 percent, so roughly 28 percent more gold per gram. Whether a particular piece is worth more depends on weight, maker and design as well, and a heavy 14 karat piece easily outvalues a light 18 karat one.
What does 18K GP mean?: Gold plated: a thin electrodeposited layer of 18 karat gold over base metal, usually brass. It is a legally honest mark and it means the piece is not solid gold. GEP, HGE and RGP are variations on the same idea, and all have essentially no scrap value.

The other hallmarks the room reads

585 375 PLAT / 950 GP / HGE / GEP 800 / 835 925

Free tools of the room

Ring Size Converter Engagement Ring Designer Jewellery Insurance Value

Elsewhere in the case

Jewellery Hallmarks: What the Stamp Inside Your Ring Means Everything the house reads

Lovenhall Ring

Read the whole piece

The mark tells you what the metal claims to be. The instrument reads the setting and the stones together and gives a range to orient you — before anyone charges you for an appraisal.

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