close up of diamond ring
Diamonds,  Education

The 4C’s: Clarity

Today, we’re going to dive into another part of the 4C’s: clarity. In this context, clarity is defined as “a diamond’s freedom from blemishes and inclusions.” The more free the stone is, the higher the final value will be. Let’s take a look at what these clarity characteristics are and how they’re judged.


Put simply, blemishes are irregularities on a diamond’s surface. Sometimes, blemishes are a perfectly natural part of a diamond’s formation within the earth. For example, irregularities in the diamond’s crystal structure can cause a grainy texture to occur.

Most blemishes, however, are the result of human contact with the stone. Nicks and pits can be formed when a diamond is struck against something, while scratches and abrasions can occur when two diamonds rub up against each other. Similarly, a poor polishing or cutting job can accidentally leave blemishes too.

Believe it or not, some blemishes are actually added on purpose—in order to enhance the appearance of the stone! For example, a diamond cutter might add extra facets, which can actually remove more obvious blemishes. Nonetheless, extra facets are technically considered to be blemishes, too, since they’re surface irregularities.


Inclusions are irregularities inside the diamond. More often than not, inclusions occur as a natural diamond is formed within the earth, but human contact can sometimes create them too.

As far as natural inclusions go, the diamond’s crystal structure or trapped impurities are the most likely causes. Inside the earth, a forming diamond is subjected to unbelievable pressure and comes into contact with all sorts of other elements. An irregular crystal structure can make a diamond look cloudy, grainy or even colored. Likewise, little bits of carbon or other elements can become trapped inside, causing dark or colored spots to appear.

On the other hand, accidental blows or a poor cutting job are usually responsible for human-created inclusions. These mishaps can cause bruises, chips, and fractures. However, just like extra facets, a purposeful inclusion can sometimes mask or eliminate other inclusions. An example of this technique is laser drilling, which can dramatically lessen the appearance of dark spots within the diamond. Nonetheless, the drilling process leaves a tiny channel behind, which counts as an inclusion of its own.

Evaluating Clarity

A jeweler’s loupe, like the one pictured above, is often used to evaluate diamonds

A skilled diamond grader uses both the naked eye and powerful magnification to observe and note clarity characteristics. If an inclusion or blemish can be seen with the naked eye, it will have the greatest affect on value. Nonetheless, even microscopic irregularities can impact appearance and durability, so diamonds are inspected under 10x magnification.

During this process, there are five main factors a grader is considering:

  1. Size: the larger the characteristic, the more visible it will be.
  2. Number: the more numerous, the more obvious.
  3. Nature: is it an inclusion or a blemish? Inclusions are usually considered more important than blemishes.
  4. Position: where is the characteristic located? For example, a diamond’s reflective properties can make one inclusion look like many, while an inclusion on the edge might not be very noticeable at all.
  5. Color: most characteristics are white or clear, but some can be colored or dark. This is known as relief.

Even though the diamond is examined at all angles, whatever is visible face-up will be the most important. However, it’s important to keep in mind that the grader isn’t thinking about aesthetics alone. Diamonds may be the toughest material on earth, but they can still suffer damage. When fractures and cavities are graded—especially if they’re large—the future durability of the diamond is considered.

GIA Clarity Scale

After all the clarity characteristics are observed and documented, the actual grade is assigned. The more effect they have on durability and appearance, the lower the final grade will be. There are eleven possible grades, ranging from Flawless (FL) to Included (I1). Check out the interactive tool below to see examples of each!

The Bottom Line

It’s always important to remember that diamond grades are highly technical and not an “objective” standard of beauty. When a diamond is graded Flawless and earns a hefty price tag, it’s ultimately about rarity.

Believe it or not, only about 2% of gem quality diamonds earn the official Flawless grade. In fact, most diamonds found in stores today are between VS and SI, yet most people would think they’re Flawless!

As you’ve learned today, inclusions and blemishes can be quite natural and completely invisible to the naked eye. Yet, even when they’re intentional, accidental or quite prominent, they aren’t necessarily undesirable. It all comes down to personal preferences.

For some, a Flawless diamond created in the lab or by mother nature might be the pinnacle of beauty. For others, a diamond with a unique pattern of dots or lines will feel one-of-a-kind and truly special—indeed, it is one-of-a-kind, as no two diamonds are alike!

If you missed our other posts about the 4C’s, be sure to read how cut and color are graded too! If you have any questions about the 4C’s or diamonds in general, we’d love to help you further. Why not contact us or pop into one of our stores? You can also browse our extensive collection of diamonds right here on our website!

We hope to serve you soon!