Did you know that gold jewelry is not 100% pure gold? Instead, it’s made from different types of gold alloys (mixtures of gold and other metals). When talking about gold alloys, you’ll often hear the term karat gold come up. But what exactly does this term mean?
Read on to understand what a gold karat is, why some karats are more popular than others, and how to choose the best karat grade for your next jewelry purchase.
What Does “Karat” Mean in Gold?
So exactly what does “karat” in gold mean? Karats of gold are simply a way of describing the purity levels of gold alloys – that is, how much gold they contain in proportion to other metal content.
The karatage system considers the total metal weight of a gold item as 24 equal parts. Any parts that are made of gold are called karats (often abbreviated as k). Basically, the more gold something has, the higher its number of karats up to 24.
Therefore, if all 24 parts of an item are gold, then it’s 24 karats. If 23 parts are gold, but one part is made of other metals, it’s 23 karats. And so on, all the way down to 1 karat, which has only a single part gold to 23 parts other alloyed metals.
While karatages can technically be anywhere between 1 and 24, in practice, most fine jewelry falls into a few standardized karat ratings. In the United States, the four most well-known are 24k, 18k, 14k, and 10k gold.
Karats vs. Millesimal Fineness
Millesimal fineness is another way of measuring gold purity. Fineness is more often used internationally, while the karats system is favored in the US and Canada.
Instead of parts per 24, the millesimal fineness system expresses gold purity in parts per thousand. You can also simply think of a fineness number as a percentage without a decimal point.
For example, a gold engagement ring that contains 750 parts gold per thousand, is described as 750 fine gold, which is 75.0% gold content. Under the karat system, the exact same ring is considered 18k gold.
Gold Purity Chart
|24K Gold||24 of 24||999 of 1000||99.9%|
|22K Gold||22 of 24||916 of 1000||91.6%|
|18K Gold||18 of 24||750 of 1000||75%|
|14K Gold||14 of 24||583 of 1000||58.3%|
|12K Gold||12 of 24||500 of 1000||50%|
|10K Gold||10 of 24||417 of 1000||41.7%|
|9K Gold||9 of 24||375 of 1000||37.5%|
Karats and Colored Gold
Because pure gold is yellow, all 24k gold is yellow gold. There’s no such thing as 24k white gold or 24k rose gold, because all colored gold is made by alloying yellow gold with other metals.
For example, the pink tint of rose gold comes from adding copper to yellow gold, while white gold is made by adding alloy metals such as zinc, nickel, silver, or palladium. White gold pieces also often undergo rhodium plating treatments to make their surfaces whiter.
This means that the less pure gold in a colored gold alloy, the less of a rich yellow tone it has. For example, 14k white gold is whiter than 18k, because it contains less pure gold and more white alloyed metals.
“Karat” or “Carat”?
Before we move on to comparing karatages with each other, a quick note on spelling. You’ll often see the word spelled as karat in the United States, and carat in Europe. In the context of talking about the purity of gold, karat and carat mean the same thing.
In another context, their meanings are very different. This is because in both countries, carat is a measure of the weight of gemstones, particularly of diamonds. For example, a 1 carat diamond weighs 0.007 ounces (0.2 grams). A 2 carat weight diamond is twice as much at 0.014 ounces (0.4 grams), and so on.
In short, carat can be used to refer to both purity of gold and gemstone weight, while karat should only be used to describe gold purity.
Comparing Gold Karats from 24k to 9k
24 Karat Gold
Despite being the highest karat, purest form of gold you can buy, 24k gold is rarely used to make jewelry in Western countries. There are a few reasons for this:
- 24k is expensive. Gold is a valuable precious metal. It’s also a highly dense and heavy metal that’s sold by weight, not volume. These factors make pure gold costlier than alloys that have been “filled out” with cheap lower density metals.
- 24k is soft. Pure gold can bend, dent, and scratch easily, which makes it impractical for everyday wear.
- 24k is very yellow. In fact, pure gold jewelry strikes many people as “too” yellow for their aesthetic taste, because they’re used to seeing the paler color of lower karatages.
The case is different in some other regions, particularly in Asia and the Middle East. In China, for instance, 24k gold jewelry outsells other gold karats. Chinese consumers usually purchase 24k jewelry as an investment or a gift (particularly a bridal gift), rather than as something to be regularly worn.
Pure gold bars are also popular investments in many countries, as gold has been a reliable store of value since antiquity.
One distinction to note is that although the terms pure gold, fine gold and 24 karat are usually used interchangeably, it’s not technically possible to create 100% pure gold. Even a 24k alloy can only be refined up to about 99.9% gold content.
22 Karat Gold
At 91.6% purity, 22k gold is visually indistinguishable from 24k pure gold. Though the inclusion of 8.4% other metals (usually copper, silver, or zinc) increases its durability somewhat, this type of gold is still soft, easily deformed, and not good at holding gemstones securely.
22k jewelry is especially popular in India, where it’s traditionally associated with status, investment, religious offerings, and weddings.
18 Karat Gold
In Western countries, 18k gold is considered the luxury standard for fine jewelry. This is because 18k (or 75% pure gold) is the highest karat rating a piece of jewelry can have while still being durable enough to wear on a daily basis.
18k gold is particularly associated with wedding rings. Gold represents eternal love, so it makes symbolic sense to include as much of it in an engagement ring or wedding band as is feasible. Modern 18k rings are designed to resist wear and tear, making this karatage a practical option as well as romantic one.
18k yellow gold is suitable for people who have metal allergies to certain metals, particularly nickel. Some 18k yellow alloys contain nickel while others don’t. But even if yours does, it’s very unlikely to trigger skin irritation as nickel makes up only a small percentage of the total metal content.
18k white gold can have higher amounts of nickel than 18k yellow gold. Nickel is a white metal, so more of it used in order to give white gold its color. If you have sensitive skin, stay away from nickel-containing white gold and choose a white gold alloy made with palladium instead.
Rose gold alloys don’t contain nickel, so rose gold is also a good choice.
14 Karat Gold
At 58.3% gold content, 14k gold is a terrific combination of affordability and strength. While it doesn’t have quite the same beautiful coloring and dazzling shine as 18k, 14k gold is still very attractive. It also has the advantage of holding gemstones more securely than softer, higher karat alloys.
Because it’s both visually appealing and relatively inexpensive, 14k gold is the most common type of gold jewelry sold in the US. As such, 14k jewelry is usually available in a wider variety of types and styles. Whether you’re looking for engagement rings, bracelets, chains, or earrings, chances are you’ll be able to find something you like in 14k gold.
However, jewelry that’s 14k (or of lower karat) isn’t recommended for people with skin sensitivity, unless you know that the alloy is nickel-free. If in doubt, ask your jeweler to confirm the metal content before buying.
12 Karat Gold
Though it was once more commonplace, 12k gold jewelry isn’t very commonly produced in most countries today. Other karatages with similar purities (10k, 14k) have become more popular and well-recognized, leaving little room in the market for 12k.
Though it’s hard to find, 12k gold is also hard to damage thanks to its high durability. This makes it a great option for plain jewelry such as stud earrings and simple rings. It’s also sometimes used as gold plating over fashion jewelry made from base metals.
10 Karat Gold
Like 12k gold, 10k gold (41.7% pure) is best used for simple jewelry. It’s more difficult to find engagement rings made in 10k, as many jewelers don’t consider such a low karat alloy appropriate for matching with diamonds and other precious stones.
If you’re looking for some simple, practical accessories that won’t break the bank, or a ring that won’t get dinged out of shape while you’re working with your hands, 10k gold is a good choice.
9 Karat Gold
Until a few years ago, 9k gold jewelry (37.5% pure gold) couldn’t legally be described as gold in the US. However, in 2018 the Federal Trade Commission relaxed the rules around jewelry marketing, and now 9k jewelry is readily available at department stores and online marketplaces.
Practically, there’s not much appreciable difference between 9k and 10k gold – they look and feel the same. But since 9k is a slightly less pure type of gold, it’s the more affordable option if you’re on a tight budget.
What are Karat Stamps?
Authentic gold jewelry often bears a quality mark or karat stamp, which is usually stamped in a discreet spot (such as the inside band of a gold ring). The purpose of this mark is to inform the consumer of how much pure gold content was used to make the piece of jewelry.
While not legally required in the United States, karat stamps are nonetheless a common practice, particularly for higher quality gold pieces of 14k purity and above.
Here are the marks to look out for, and what they mean.
- 18 Karat, 18K, or 750. Any of these stamps disclose that 18 of 24 parts (75%) of the alloy are made of gold.
- 14 Karat, 14K, 585, or 583. 14 of 24 parts (58.3%) of the alloy are gold. 14k alloys must have at least 58.3% gold content, as shown by a 583 mark, but can often have slightly more at 58.5%, as shown by a 585 mark.
- 10 Karat, 10K, or 417. 10 of 24 parts (41.7%) of the alloy are gold.
- GF, GP or GEP. Standing for gold-filled, gold plated, and gold electroplated, respectively. These marks are typically found next to a karat number – for example, 14K GF.
- Vermeil or 925. The piece is made from sterling silver and has a thin top coating of gold.
What is the Best Karat Gold?
18k gold and 14k gold are widely considered to be the best choices for fine gold jewelry, and comprise the vast majority of engagement ring and wedding rings sales. Both possess an ideal combination of beauty, shine, and durability, which has kept them in high regard for centuries.
24k gold is the highest quality and most valuable karatage, but is less popular due to its expense and ease of damage. For jewelry of this karat type, shop for something you’ll wear for formal occasions only, or buy it as as investment.
12k, 10k, and 9k gold are good options if you’re looking to price shop for affordable, everyday jewelry that you can wear while working with tools, playing sport, or doing other physical activities.
Thanks for reading to the end! If you’d like to learn about another popular jewelry metal, then feel free to check out our guide to platinum jewelry.