Understanding the 4 Cs of Diamond Quality

Understanding the 4 Cs of Diamond Quality
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The world of gemstones is a pretty dazzling place (literally), especially when it comes to diamonds.

If you have been researching the different facts about diamonds in preparation for getting an engagement ring, you will have likely come across the 4 Cs of diamonds.

This is a set of values that are used by jewellers and other professionals in the business of gemstones and diamonds that are used to assess the overall value of a diamond, and to accurately assess a diamond takes a lot of training.

So, what are these 4 C’s, and how are they used to determine the cost of that diamond engagement ring that you want to buy?


If you are looking to buy a ring for any occasion that has a diamond as its keystone, you will see the different types of cuts come up. These cuts are the first C in assessing a diamond’s quality.

The most common diamond cuts are round brilliant, princess, emerald, radiant, marquise, and pear, but there are many more.

However, when it comes to cost, you will find that the most expensive cut is the round brilliant cut, but any jewellers Hertfordshire will have a different array of cuts for you to choose from, so shop around.


Next is clarity which, for people who are not in the field of working with precious gemstones, can be confusing. Aren’t all diamonds clear?

Diamond clarity refers to the number and size of the inclusions, or flaws, that are found in a diamond. It is typically graded on a scale from flawless (FL, IF) to heavily included (I3). Clarity has an impact on the value of a diamond and affects its brilliance and sparkle. As you can imagine, diamonds with a high FL and IF index are more expensive.

If you are going to buy an engagement ring, the average clarity that you will find will be VS2 (very slightly included). However, you can shop around and find an engagement ring store that offers higher-clarity diamonds.


This can be confusing, too. Aren’t all diamonds, by their definition, clear? Well, yes and no. In actuality, the color of a diamond relates to the hue.

Diamonds are often graded on a scale that ranges from colorless to fancy (deeply saturated) colors, with the grading taking into account hue, tone, and saturation.

So, you can get black, blue, and even green diamonds, which are rarer and may be more expensive than clear ones.

Carat Weight

You’ve heard of the word carat concerning gold, but what about diamonds?

Carat is a unit of measurement used by jewelers to determine the weight of a diamond. It is equal to 200 milligrams and is often used to indicate the size of a diamond. The higher the carat weight, the larger the diamond and the more valuable it is.

Of course, the carat weight is not the only way to determine the value of the diamond; you can get a heavy diamond that has low clarity, which will be cheaper than a small, clear diamond.

If you are choosing an engagement ring with a diamond as the core stone, the average carat will be about 0.9 carats.