Gold Purity by Country: a guide to gold carats, fineness and hallmarks
When you buy a gold piece of jewellery, you're choosing more than a beautiful item — you're choosing a particular level of gold purity, durability and value.
But gold purity isn't measured or regulated in exactly the same way around the world. A ring stamped 375 might be completely familiar to a British buyer, while a 333 mark could indicate Danish gold, an 800 mark may point to Portugal, and 750 is widely recognised as 18ct gold across Europe.
So, what do these numbers actually mean? Why do different countries use different gold standards? And how can you tell how much pure gold is in a ring?
This guide explains gold purity by country, the meaning of common gold hallmarks, and what you should know when buying or identifying gold jewellery.
What Does Gold Purity Mean?
Pure gold is 24 carat (24ct), but pure gold is relatively soft and isn't particularly practical for everyday jewellery. It can scratch, bend and wear more easily than an alloy designed for regular use.
For this reason, gold in jewellery is normally mixed with other metals such as silver, copper, zinc or palladium. These additional metals improve strength, durability and, depending on the alloy, colour.
Gold purity is usually expressed in one of two ways:
• Carat (ct) — commonly used in the UK and many other countries.
• Karat (k or kt) — more commonly used in the United States and Canada.
• Millesimal fineness — a number showing the proportion of pure gold in parts per thousand.
The carat system is based on 24 parts. For example:
• 9ct gold = 9 parts gold out of 24 = 37.5% pure gold
• 14ct gold = 14 parts gold out of 24 = 58.5% pure gold
• 18ct gold = 18 parts gold out of 24 = 75% pure gold
• 22ct gold = 22 parts gold out of 24 = 91.6% pure gold
• 24ct gold = virtually pure gold
This is where fineness marks such as 375, 585, 750 and 916 come in. The number represents the amount of pure gold per 1,000 parts.
For example, a 750 gold hallmark means that at least 750 parts per 1,000 are pure gold — equivalent to 18ct.
UK Gold Standards: 9ct, 14ct, 18ct and 22ct
The UK has a long-established hallmarking system designed to protect consumers buying precious-metal jewellery. A UK hallmark confirms that an item has been independently tested and verified for its precious-metal content.
The main UK gold fineness standards include 375, 585, 750 and 916, corresponding to 9ct, 14ct, 18ct and 22ct gold respectively.
9ct Gold (375)
9ct gold contains 37.5% pure gold and is one of the most popular choices for everyday jewellery in the UK.
Because it contains a higher proportion of alloy metals than higher-carat gold, 9ct gold is relatively hard and durable. This makes it particularly well suited to rings that are worn every day.
Its colour can vary depending on the metals used in the alloy. Yellow 9ct gold tends to have a lighter appearance than 18ct, while rose gold gets its warmer pink tone from a higher proportion of copper.
For anyone looking for an affordable gold ring that can withstand regular wear, 9ct gold is a practical and popular choice.
14ct Gold (585)
14ct gold contains 58.5% pure gold and is marked 585.
It occupies a useful middle ground between 9ct and 18ct gold. It contains considerably more pure gold than 9ct while generally being more resistant to everyday wear than 18ct.
14ct gold is particularly popular in the United States and is also widely encountered in jewellery from other parts of Europe and around the world.
In the UK, 14ct gold is a recognised hallmarking standard, although 9ct and 18ct remain more familiar choices for many British jewellery buyers.
18ct Gold (750)
18ct gold contains 75% pure gold and is marked 750.
Its higher gold content gives it a richer, deeper yellow colour than 9ct gold, making it a particularly popular choice for fine jewellery, engagement rings and wedding rings.
18ct gold is also widely used internationally, so a 750 hallmark is one of the most useful gold purity marks to recognise when buying or identifying jewellery.
It is softer than 9ct and 14ct gold, but still durable enough for many types of everyday jewellery when properly cared for.
22ct Gold (916)
22ct gold contains approximately 91.6% pure gold and is marked 916.
Its high gold content gives it a distinctive, rich yellow colour. However, the increased gold content also makes it softer than 9ct, 14ct or 18ct gold.
22ct gold is particularly associated with traditional jewellery from South Asia and parts of the Middle East, as well as certain traditional gold jewellery styles in the UK.
It can be an excellent choice for substantial plain bands and traditional pieces, although highly intricate settings may be better suited to a harder gold alloy.
The History of 12ct and 15ct Gold in the UK
If you've ever looked at antique jewellery, you may have encountered gold marked 12ct or 15ct.
These are historical British gold standards that are no longer used as current UK hallmarking standards. 12ct gold corresponds to 500 fineness, while 15ct gold corresponds to 625 fineness.
They were particularly associated with Victorian and Edwardian jewellery, so you may encounter these marks on antique rings, brooches, pendants and other period pieces.
In 1932, the UK moved away from the 12ct and 15ct standards and introduced 14ct gold at 585 fineness. This brought the British system closer to standards already widely used internationally.
As a result, a genuine antique piece carrying a 12ct or 15ct mark can be particularly interesting to collectors and anyone interested in the history of jewellery.
Why Is 14ct Gold So Popular?
The 14ct (585) standard deserves particular attention because it has become one of the most widely recognised gold standards internationally.
With 58.5% pure gold, 14ct provides a balance between gold content, durability and price.
Compared with 9ct gold, it contains significantly more pure gold. Compared with 18ct, it generally offers greater resistance to everyday wear.
This makes 14ct particularly popular for engagement rings, wedding rings and other jewellery designed to be worn regularly.
Danish 8ct Gold (333)
Not every country uses the same minimum gold purity standards as the UK.
One interesting example is 8ct gold, marked 333, which has historically been used in Denmark and other parts of Scandinavia.
The 333 fineness mark means that 333 parts per 1,000 are pure gold — approximately 33.3%.
Because it contains a greater proportion of other metals, 8ct gold can be harder and more affordable than higher-carat gold. Its lighter, more muted colour also gives it a distinctive appearance.
Importantly, a piece marked 333 should not automatically be assumed to be fake simply because 333 isn't a standard UK gold fineness. Gold standards vary between countries.
If you're identifying an older or imported ring, the hallmark can provide an important clue about its origin.
Portugal's Distinctive 19.2ct Gold Standard
Portugal has one of Europe's most distinctive gold traditions, particularly when it comes to traditional jewellery.
Portuguese gold is famously associated with 800 fineness, equivalent to 19.2ct gold.
That means the alloy contains 80% pure gold, placing it between 18ct and 22ct gold in terms of purity.
The 800 standard is particularly associated with Portuguese goldsmithing traditions and elaborate gold filigree, known as filigrana. These intricate pieces are especially associated with northern Portugal and have a long cultural history.
So, if you encounter Portuguese jewellery marked 800, you're looking at a gold standard that is somewhat unusual compared with the more familiar 375, 585 and 750 marks found elsewhere in Europe.
French Gold Standards: A Changing History
France has historically had stricter rules around precious-metal standards than some other European countries.
For much of the 20th century, French legislation recognised 750 fineness (18ct) as a principal gold standard. However, the rules changed in the 1990s.
Legislation introduced in 1994 recognised additional gold finenesses, including 585 (14ct) and 375 (9ct), although these lower-purity products were subject to different naming and guarantee requirements at the time.
This is an important distinction when researching older French jewellery: a piece made or sold under historical French regulations may not follow exactly the same conventions as a modern piece.
Today, 750/18ct gold remains particularly important in French fine jewellery, but French gold jewellery can also be encountered in other recognised finenesses.
Italy: 18ct Gold and the 750 Fineness Standard
Italy has a long and internationally respected tradition of goldsmithing, with jewellery-making centres including Vicenza, Arezzo and Valenza. If you've ever bought or inherited Italian gold jewellery, you're likely to encounter a 750 fineness mark.
In Italy, the recognised legal gold finenesses are 750, 585 and 375, corresponding to 18ct, 14ct and 9ct gold respectively. Italian precious-metal jewellery is marked with its fineness in parts per thousand, alongside an identification mark that identifies the manufacturer or importer and the province associated with the business.
Of these standards, 750 gold (18ct) is particularly important in Italian fine jewellery. With 75% pure gold, it offers the rich colour and high gold content associated with fine jewellery while remaining practical enough for rings and other pieces designed for regular wear.
Italian jewellery is also a useful reminder that a familiar-looking gold hallmark doesn't necessarily mean a piece was made in the UK. A ring marked 750 could have been manufactured in Italy, France, the UK or elsewhere, so the accompanying maker, sponsor or identification marks can provide valuable clues about its origin.
Quick Reference – Gold Purity Around the World:
Tip: Gold standards and hallmarking requirements can vary depending on the country, the age of the jewellery and whether the item is imported. A hallmark should therefore be interpreted in context rather than in isolation.
Why Does Gold Purity Matter When Buying a Ring?
Understanding gold purity can help you choose a ring that's right for your budget, lifestyle and personal preferences.
1. Durability
Lower-carat gold such as 9ct and 14ct generally contains more alloy metals, which can make it harder than high-carat gold.
For a ring worn every day, durability is an important consideration.
2. Colour
The higher the gold content, the richer and deeper the natural yellow colour tends to be.
However, the final colour also depends on the other metals used in the alloy. That's why yellow, white and rose gold can all have different appearances even when they have the same carat.
3. Gold Content
Higher-carat gold contains more pure gold.
An 18ct ring, for example, contains 75% gold, while a 9ct ring contains 37.5%. This difference can affect both the intrinsic value of the metal and the appearance of the finished piece.
4. Price
Gold purity is one factor that can influence the price of a ring, but it isn't the only one.
The final price can also reflect the weight of the jewellery, craftsmanship, gemstones, design, brand and current gold prices.
5. Hallmarks
If you're buying gold jewellery in the UK, the hallmark is an important part of understanding what you're purchasing.
A complete UK hallmark includes a sponsor's or maker's mark, a metal and fineness mark, and an Assay Office mark. The fineness number tells you the precious-metal content, while the Assay Office mark identifies where the item was tested.
For example, if you see 375 on a UK gold ring, it indicates 9ct gold. A 750 mark indicates 18ct gold.
There are also minimum weight exemptions for compulsory hallmarking, so not every small item will necessarily carry a full UK hallmark.
What Do Gold Hallmark Numbers Mean?
If you're wondering “What does 375 gold mean?” or “What does 750 mean on a ring?”, the answer is straightforward:
• 333 = 33.3% gold = 8ct
• 375 = 37.5% gold = 9ct
• 500 = 50% gold = 12ct
• 585 = 58.5% gold = 14ct
• 625 = 62.5% gold = 15ct
• 750 = 75% gold = 18ct
• 800 = 80% gold = 19.2ct
• 916 = 91.6% gold = 22ct
• 999 = 99.9% gold = 24ct
These numbers are often the quickest way to identify the gold purity of an unfamiliar piece.
Final Thoughts: Gold Purity Tells a Story
Gold may be one of the world's most universal precious metals, but the way it is measured and regulated varies considerably from country to country.
From 333 Scandinavian gold and Britain's 375 9ct gold, through to Portugal's distinctive 800 19.2ct standard and the widely recognised 750 18ct mark, gold hallmarks can reveal much more than purity. They can also provide clues about a piece's age, origin and history.
Whether you're buying a new gold ring, identifying an antique piece or trying to understand a hallmark you've discovered on a family heirloom, knowing the difference between carat, fineness and hallmarking makes it much easier to understand exactly what you're looking at.
At Betty's Ring Box, we want you to feel confident about the jewellery you buy. Our gold jewellery is clearly marked with its carat and hallmarked to UK standards where required, so you can understand exactly what you're buying.
If you're unsure about the hallmark or gold purity of a particular ring, we're always happy to help.