TL;DR A 750 stamp means 750 parts of pure metal per thousand, or 75%. On rings, chains, earrings and watch cases it almost always means 18 karat gold, because 18 of 24 karats is exactly 75%. A 750 silver standard did exist, mostly in Austria-Hungary, but it is rare. Colour, weight and the neighbouring marks settle it.
A 750 stamp is a purity number, not a metal name: 750 parts of pure metal in every 1,000. The same three digits sit on an Italian gold chain and, far less often, on a 19th-century Austrian silver spoon. On jewelry, read 750 as 18 karat gold until the piece gives you a reason to think otherwise.
Is a 750 stamp gold or silver?
On jewelry, a 750 stamp nearly always means 18 karat gold. Gold is the precious metal routinely sold at 75% purity, since 18 divided by 24 is 0.75. Silver at 750 was a legal standard only in a few places, mainly Austria-Hungary and 18th-century Russia, so 750 silver usually turns up on antique spoons and holloware, not rings.
Use this table as a first pass. It reads the evidence you can see without a loupe or a lab.
| What you see | Most likely metal |
|---|---|
| 750 on a ring, chain, clasp or watch case in yellow or rose metal | 18 karat gold |
| 750 beside "18K", "18KT", "K18" or "AU" | 18 karat gold |
| 750 beside an eagle's head (France) or a five-pointed star with a number and province code (Italy) | 18 karat gold |
| 750 beside a leopard's head, anchor, rose or castle (UK assay office) | 18 karat gold |
| 750 beside "GP", "GF", "HGE" or "RGP" | Gold plate or gold filled over base metal |
| White metal that tarnishes, with a Diana head and the numeral 4 | 750 silver, Austria-Hungary, 1872 to 1922 |
| White metal with no other marks | Could be white gold or silver; test it |
Why does 750 equal 18 karat gold?
The karat system divides gold into 24 parts, and 18 karat gold holds 18 parts pure gold to 6 parts other metal. Eighteen twenty-fourths is 75%, written in the millesimal system as 750. The remaining 25% is usually silver, copper, zinc or palladium, and that mix sets the colour: yellow, rose or white.
| Millesimal stamp | Karat | Pure gold |
|---|---|---|
| 375 | 9k | 37.5% |
| 585 | 14k | 58.5% |
| 750 | 18k | 75.0% |
| 916 | 22k | 91.6% |
| 999 | 24k | 99.9% |
These are the gold standards in UK hallmarking law, which also allows 990. The crown that often sits beside a British 750 is an optional pictorial mark for gold, not part of the fineness claim.
Which hallmarks appear next to 750 gold?
The marks beside 750 tell you who tested the gold. A British hallmark pairs 750 with a sponsor's mark and an assay office mark: leopard's head for London, anchor for Birmingham, rose for Sheffield, castle for Edinburgh. France uses an eagle's head for 18 karat gold. Italy adds a star with a registration number and province code.
Countries that signed the 1972 Vienna Convention on precious metals can also strike the Common Control Mark: a pair of balance scales with 750 inside. In the United States there is no government assay, so "18K" or "750" is the maker's own claim, backed by the Federal Trade Commission's jewelry guides rather than an independent test. See the gold and silver hallmarks guide for the wider system.
When does a 750 stamp mean silver?
A 750 stamp means silver mainly on Austro-Hungarian pieces. The 1866 Austrian system allowed four silver standards, 950, 900, 800 and 750, and from 1872 the Diana head mark carried a numeral from 1 to 4, where 4 meant 750. Russia's 72 zolotnik standard is also 750 fine; it was the legal minimum from 1779 to 1798.
Outside those cases, a white 750 piece is more often 18 karat white gold, which is normally plated with rhodium and never turns black. Our 750 silver mark guide covers silver at this standard in more depth, and the Russian 84 silver mark page explains the zolotnik numbers.
How can you tell 750 gold from 750 silver at home?
Density is the most reliable home test. Silver weighs about 10.5 grams per cubic centimetre, while 18 karat gold alloys weigh roughly 15 to 16. Weigh the piece in air, then suspended in water on a kitchen scale; divide the dry weight by the difference. A result above 14 points to gold, around 10 to 10.5 to silver.
Three quicker checks narrow it further:
- Look for tarnish in crevices. Silver goes yellow, brown, then black. 18 karat gold does not tarnish in normal wear.
- Hold a strong magnet close. Gold and silver are both non-magnetic, so a pull means steel or nickel under plating, whatever the stamp says.
- Check the edges and clasp under a loupe. Worn plating shows a different coloured metal underneath.
A jeweller with an XRF analyser can read the alloy in seconds without marking the piece. Our silver testing guide walks through the acid and ice tests.
Can a 750 stamp be fake?
Yes. A stamp is a claim, and only an assay office hallmark is an independent test of it. Plated jewelry often carries 750 or 18K beside GP, GF, HGE or RGP, which mean gold plated, gold filled, heavy gold electroplate and rolled gold plate. A 750 with no maker's mark on a cheap chain deserves suspicion.
Weight is the giveaway on chains: an 18 karat chain feels far heavier than a plated brass chain of the same size. When the piece matters, pay for a test before you pay for the gold.
Key takeaways
- A 750 stamp means 75% pure metal; on jewelry it almost always means 18 karat gold.
- 18 of 24 karats is 0.75, which is why 18 karat gold and 750 are the same standard.
- 750 silver is rare and mostly Austro-Hungarian, marked with a Diana head and the numeral 4 between 1872 and 1922.
- Silver tarnishes and weighs about 10.5 g/cm3; 18 karat gold does not tarnish and weighs about 15 to 16 g/cm3.
- GP, GF, HGE or RGP beside 750 means a thin gold layer over base metal, not solid gold.
Sources
- Hallmarking Act 1973 (Application to Palladium and Amendment) Regulations 1998, legislation.gov.uk
- Convention on the Control and Marking of Articles of Precious Metals (Common Control Mark)
- Fineness, Wikipedia
- FTC Guides for the Jewelry, Precious Metals, and Pewter Industries, 16 CFR Part 23
Frequently Asked Questions
What does 750 mean on a ring?
On a ring, 750 means the metal is 75% pure gold, which is 18 karat. The other 25% is an alloy of metals such as silver, copper or palladium that sets the colour. A ring stamped 750 is solid gold unless GP, GF, HGE or RGP appears beside the number.
Is 750 gold real gold?
Yes. 750 gold is solid 18 karat gold, 75% pure, the exact standard that the French eagle's head hallmark guarantees. It is harder than 22 or 24 karat gold, so it suits rings and bracelets, and it holds more gold than 14 karat, which is only 58.5% pure.
Is 750 better than 925?
They measure different metals. 750 on jewelry usually means 75% gold, while 925 means 92.5% silver, known as sterling. Gram for gram, 18 karat gold is worth far more than sterling silver because gold is many times more expensive than silver on the bullion market.
Does 750 white gold tarnish?
No. 18 karat white gold does not tarnish the way silver does. Most white gold is plated with rhodium for a brighter white, and that plating can wear thin over years, letting a faint yellow tone show through. A jeweller can replate it; silver would instead turn grey or black.
What does 750 mean on a watch?
A 750 stamp inside a watch case or on a bracelet means the case or bracelet is 18 karat gold. Look for a maker's mark or an assay office mark beside it. Steel watches with gold plating carry no 750 on the steel parts, and plated cases often add words such as plaque or plated.
