What is 18-Karat Gold?

Knowing the difference between different kinds of golds is one of the most important things to keep in mind when buying gold jewelry. Golds are measured using the karat system and one of the most popular choices for wedding and engagement rings is 18-karat gold.

The different kinds of gold include 24-karat, 22-karat, 18-karat, 14-karat, and 10-karat. So, what is 18-karat gold exactly? 18-karat gold is well known by jewelers for having a good balance between purity and durability and it often surprises people with how affordable it is compared to its 22K and 24-karat counterparts.

In this article, we will go through everything you need to know about the basics of what 18-karat gold is, its advantages and disadvantages compared to the other karats, and how to recognize and test your gold jewelry to make sure it is 18 karats. So, let’s start out with the basics.

Is 18K Gold Good?

When jewelry makers measure the purity of gold, they use the karat system to grade each cut. 24-karat gold is the highest you can go and is 100% completely pure. Lower karats use other metals to improve their durability and, the lower you go, the more various kinds of metals are inside the gold.

Looking for the best gold testers? We reviewed the top 5 gold testers here.

18-karat gold is roughly 75% pure so, in comparison to 24-karat gold, it is more durable but sacrifices some of its purity to do so. You will have to worry about scratches and dents much more so in a 24-karat gold ring than in an 18-karat one.

More times than not, the other metals you will find in 18-karat gold are ones such as copper, zinc, and nickel. These metals blend in with the gold fairly well and an untrained eye typically cannot see them unless they look very closely.

Pros and Cons of 18-Karat Gold

Of course, there are plenty of things to consider when buying any type of gold jewelry. 18-karat gold is not perfect but neither is 24-karat gold either. They each have their pros and cons, so let’s take a look at what 18-karat gold can and can’t offer to you.


  • 18-karat gold has great balance between purity and durability.
    It looks beautiful, especially with a quality diamond on it and it can last a long time even if you plan to wear it frequently. This gold is perfect for wedding or engagement rings you want to show off.
  • There is also plenty of variety in color when it comes to 18-karat gold.
    You will be able to find the classic yellow gold, white gold, or even rose gold with some searching. The only difference between these 18-karat golds are the metal alloys in them.


  • It’s not cheap. 18-karat gold is by no means inexpensive and will usually cost you at least $1,000 if you are looking at an 18-karat ring.
  • You need to be careful with it. It is more durable than its 24-karat and 22-karat counterparts but it is certainly not invincible. If you are not careful with it, your gold jewelry could get easily scratched or dented and may require some repair that can cost you even more money.


18-Karat Gold Vs. Other Karats

24-Karat vs. 18-Karat

There really is no substitute for 24-karat gold and it is certainly the best looking and rarest kind of gold you will find out there. However, 24-karat gold is very easily scratched and dinged which makes it risky to wear frequently.

18-karat gold certainly has the advantage on 24-karat gold in this regard. You can show off your gold jewelry with much less worry with 18-karat without sacrificing too much in terms of looks as well.

22-Karat vs. 18-Karat

These two golds are fairly similar in that they both look gorgeous but have a bit more durability than the 100% pure 24-karat gold.

However, 22-karat gold is still a good bit more expensive and it is also fairly fragile in comparison to 18-karat gold as well. You will not be sacrificing too much in terms of beauty buying an 18-karat over a 22 at all.

18-Karat vs. 14-Karat

14-karat gold will usually save you at least a few hundred dollars if you choose this over the 18-karat option. Plus, you can pretty safely wear 14-karat gold jewelry every day without having to worry much about damaging it.

On the other hand, most people begin to see a bit of a drop off in terms of shine when it comes to 14-karat gold and most people will agree that 18-karat gold looks better aesthetically.

10-Karat vs. 18-Karat

While 10-karat gold is certainly very durable it is noticeably different from 18-karat gold in terms of looks. More than half of this gold is other metal alloys and the lack of purity is pretty easy to see when you put them next to each other.

Although, 18-karat gold is going to be much more expensive than 10-karat gold and, if you are on a budget for gold jewelry, 10-karat gold will last you a lifetime for a very reasonable price.

For more Gold comparisons, read this: What’s the difference between 14K, 18K, and 24K Gold Jewelry. Which is better?


How to Recognize 18-Karat Gold Jewelry

When you go into a jewelry store the gold jewelry you will see will almost always have the karat number stamped on it. In most cases, the stamp will simply say “18K” or “18KT”.

You may also see the karats expressed in terms of a percentage. In this case, 18-karat gold would have a stamp that says “.75” or “750” to show that it contains 75% gold. Some percentages will not have exactly 75 but if it is reasonably close to that number it is still considered 18-karat gold.


Testing if your 18-Karat Gold is Real

Sometimes you will want to test your gold jewelry to see if it is truly 18 karats. One way to do this is through acid testing, which some jewelry stores can do for you, or you can buy one for yourself.

Specifically, you expose a piece of the gold to nitric acid and observe its reaction. The color change in the alloy can prove whether or not it is 18-karat gold or something else.

The process of this test is fairly simple and should not cause any noticeable damage to your jewelry if you do it correctly. Let’s go through the steps of this process so you can know for sure if your gold jewelry is 18 karats.

Step 1: Scratch the Jewelry

Of course, you do not want to leave a noticeable scratch on your jewelry so this is typically done by using a testing stone to rub it in an inconspicuous spot on the jewelry so the scratch is hardly noticeable.

Step 2: Use the Testing Needle

If you have a testing kit for yourself, there should be a needle labeled “18K”. Rub this needle on the stone you used to scratch your jewelry right next to the gold mark on it.

The needle itself should leave a mark, which you can use to compare its color to the mark on the stone after the acid treatment. Some testing kits may not come with these needles and, if they do not, just move on to the next step.

Step 3: Apply the Acid

There should be some nitric acid labeled “18K” that you should apply to the gold scratch on the stone and your needle mark if you have it. The acid is specifically produced to react to 18-karat gold if the two meet.

Step 4: Look at the Color Change

Provided your gold is 18 karats or above, the color should barely change or not change at all. It should also look the same as the scratch mark on your needle if you have the needle in your testing kit.

If the gold is less than 18 karats, the scratch mark will disappear after a while and it is more likely 14-karat or less. If the color of the scratch mark only becomes a bit rusty and does not go away, the gold is probably only 1-2 karats less than 18-karat gold.


Who Should Buy 18-Karat Gold?

18-karat gold is great if you are looking for gold jewelry that is not too soft but still has that beautiful pure shine that higher karats display so well. It is a great compromise for those that are looking for both durability and purity.

Also, for those that are allergic to some metal alloys like nickel, it is a better option to go for 18-karats rather than 14. It is much less likely you will get some kind of rash or reaction with a higher karat gold due to the fact it contains less metal alloys.

You should buy 18-karat gold if you are looking for a good looking, durable piece of jewelry that you plan to wear often but not every day.

If you are worried about allergic reactions to nickel, take a read of our other articles:

Where to Buy Gold Jewelry

You can buy gold jewelry at your local jewelry store or you can check out some of the listings on Amazon as well.

We also recommend online retailer, James Allen, which lets you take a 360-degree look at a diamond, sapphire, or any other stone before it is set in gold.

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Carl Jones

Carl has been involved in the jewelry business since his youth. Growing up in South Africa his parents were jewelers who worked in the industry for decades.

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