Out of tens of diamond characteristics, the 4Cs are the ones that everyone needs to pay top attention to, and out of these 4 (cut, color, clarity, and carat), you need to carefully educate yourself a little more about diamond clarity.

Diamond Clarity refers to the absence of birthmarks that are common with almost all diamonds, these birthmarks can be internal (inclusions), and surface irregularities (blemishes). Diamonds without inclusions or blemishes are graded as flawless on the scale but are rare (only 0.5-1% of diamonds make it to this grade), thus affecting its value.

The clarity of a diamond visible to one’s eye will affect it’s brilliance. That’s why clarity is often more important than the color of the diamond you choose.

What Are Diamond Inclusions and Blemishes?

Diamond Inclusions term is basically a fancy way of referring to the flaws that are visible (to visible eye or under a magnifier) in different kinds of diamonds. Some are internal and others occur on the surface. Beyond this, there are different types of inclusions that are classified based on how they were formed.

When a diamond has inclusions (which happens in only +99% of the times), it does affect the way light interacts with the stone. Without inclusions, the light is able to travel through the diamond without any “road blocks,” so to speak.

The type, size, location of inclusion determines how much “blocking” will occur to the light passing through the diamond, more on this shortly.

What Causes Diamond Inclusions?

When a diamond is forming, small crystals can become trapped on the diamond.

As the crystal grows, irregularities can develop in its atomic structure. These crystals might remain after the stone has been cut and polished and they can affect a diamond’s appearance and even it’s durability.

Diamond Inclusion vs. Blemishes

Diamond inclusions are crystals (or less-common a foreign material) that have been formed inside/within the stone itself, inclusions are less visible since they are a bit deeper in the diamond.

While blemishes appear on the diamond’s surface and do not extend into the diamond’s inner structure. For instance, a simple scratch would be called a blemish, not an inclusion since it doesn’t extend beyond the surface of the stone.

It’s worth to mention that blemishes have more impact on diamond grading, appearance, and even price than internal imperfections (inclusions).

We also believe it’s important that this classification isn’t standard 100% on the web (even on stores), they usually refer to both types as just “inclusions”, in a context where they refer to internal & external features/imperfections.

Inclusion Types

There are a lot of inclusion/blemishes types that can be found in almost any diamond, and that’s not an issue all the times, what’s more important is knowing size, type, color, and location of an inclusion to know how much it will affect the diamond brilliance and even durability, let’s take a deeper look:

1. Laser drill hole

One such inclusion not usually visible to the naked eye. Usually, diamond cutters use lasers to drill into a diamond to remove a more obvious black inclusion. These inclusions are usually microscopic but can no doubt, affect the diamonds value.

If you read anything about “laser drilling” in the diamond description then it’s likely this inclusion exists. On a diamond sketch it will be indicated as a red dot with a green circle around it.

2. Crystal

Also known as a baby diamond because it often resembles small bits of mineral deposits within a larger diamond. In a diamond clarity plot a crystal will be denoted as a small red circle. These inclusions can occur in different colors including black, white, rarely green and sometimes red.

If you do come across crystals it’s advised to only choose stones that have white crystals as they’re much more difficult to see with the naked eye. Darker crystals are easier to see with the naked eye, and thus you should avoid any diamonds with this type.

3) Needle, pinpoint and cloud

These are actually types of crystals. A needle is one that is long and thin (like a needle) and is usually white or translucent. The crystal is long instead of round due to pressure when being formed. You’ll notice these as diagonal lines on the clarity plot.

Pinpoints are the most common types of crystal inclusions and look like tiny white dots, usually only visible under extreme magnification. Some pinpoints can occur in grey or black. A pinpoint is usually denoted as a tiny red dot on a plot.

A cloud is formed from more than 3 pinpoints and denoted as a broken circle on the clarity plot. It appears white and hazy (like clouds). Tiny, subtle clouds don’t pose a huge threat but larger ones can affect light performance.

4) Twinning wisp

This type is basically when the crystal plane in the diamond twists, and is formed when there are defects in the diamonds crystal structure. When a diamond is being formed, it can be stopped mid-way due to bad conditions. When the formation resumes it can cause twinning wisps to appear within the stone.

On a diamond clarity plot it will usually show up as a twisting line with perpendicular lines through it (kind of like a railroad). These inclusions happen most in fancy shaped diamonds (shapes other than round).

5) Knots

These are inclusions that reach the finished surface of the diamond, they are easier to see with the naked eye. You may even be able to see where this inclusion meets the diamond surface, giving the impression the stone has a raised area on it. Knots do affect the durability of a diamond, and since they can be seen with your own eyes, they’re not ideal.

On a diamond grading report you’ll see it as a red oval surrounded by a green oval.

6) Feathers

They are called so because the inclusion resembles a birds feather. It’s generally transparent, but basically it’s just a tiny crack inside the diamond. Unfortunately, though they’re small they can affect durability.

On a grading or clarity report, you’ll see feathers denoted as a squiggly line.

7) Chips

A small opening in the diamond surface, usually near the edges. These can be caused by anything and are often visible to the naked eye. They can be “fixed” if you want to re-cut or polish the diamond, but if it’s a rather large chip, you can end up losing overall size (i.e. carat).

On a grading chart, it’s seen as a ^ symbol.

8) Cavity

If you’ve ever been to a dentist, you know what a cavity is. In the diamond clarity world, it’s the same thing. When a pocket in the diamonds surface collects dust, dirt or oils and they become trapped. They’re usually tiny and can only be seen with magnification but they form when an internal inclusion falls out during polishing.

These are denoted as ovals with lines going through the center on grading charts.

9) Bruise

bruise usually appears on the crown part of a stone but can also can show up anywhere. They are usually caused by diamond cutters via a hard hit to the surface of the diamond or excessive force when polishing. Because these bruises can extend down to the interior of a diamond, they are inclusions and not blemishes.

On grading reports these are marked as an x.

10) Etch channels

If you happen to notice a hollow tunnel or worm-hole like channel, you may think it’s a laser drill hole. But these are actually called etch channels. They occur when the diamond is forming and being pushed from the inner mantle of the earth out to the surface crust.

They are basically wounds from the intense heat in the earths crust and inner core. These inclusions can make cleaning difficult, as particles can trap in them.

11. Natural & indented Natural

The final two types of inclusions are natural and indented natural inclusions. These are often mistaken for chips, but on the contrary they are left in the diamond purposefully by the cutters. Usually found on the girdle edges of stones they are not usually anything to worry about. With indented naturals they are not only on the surface, but also slightly into the structure of the stone.

The GIA Diamond Clarity Scale

The GIA -founders of 4Cs- Clarity Scale contains 11 grades, and is intended to gauge the level of flawlessness of a particular stone. The scale ranges from I to F (Included vs. Flawless) and when judging a diamond 10x and 20x zoom is often used.

Most diamonds fall into the VS (very slightly included) or SI (slightly included) categories. Flawless diamonds are exceptionally rare that it is possible to spend a lifetime in the diamond jewelry business without seeing one.

Before talking a little about each group of grades, it’s important to mention that when we refer to “included” or “slightly included”, it means under 10x magnification and not to naked eye:

  • Flawless (FL): No inclusions and no blemishes are visible to a skilled grader
  • Internally Flawless (IF): No inclusions but only minor blemishes are visible (again, under 10x magnification)
  • Very, Very Slightly Included (VVS1 and VVS2.: Inclusions are so slight that they are difficult to see for a skilled grader
  • Very Slightly Included (VS1 and VS2.: Inclusions are minor and are observed with difficult for a skilled grader to see
  • Slightly Included (SI1 and SI2.: Inclusions are noticeable to a skilled grader
  • Included (I1, I2, and I3): Inclusions are obvious under magnification. This may affect the transparency and brilliance of the diamond

Many inclusions and blemishes are too tiny to be seen by the naked eye. To someone who is untrained, A VS1 and SI2 may look the same. However, these diamonds quite different in terms of quality.

This is the reason why loupes are used. Expert and accurate assessment of diamond clarity is a crucial factor in buying diamonds.

How Clarity Grades Look in Real Life

Here are some pictures that will help you recognize the various types of diamonds on the GIA scale.

Flawless (Grade: FL – IF)

Flawless diamonds are exactly that – they have no flaws. Internally flawless diamonds are diamonds that do not have any inclusions, but may have some surface blemishes only visible with more than 10x zoom. These are the priciest diamonds you’ll find.

Very Very Slightly Included (Grade: VVS1 & VVS2.

These diamonds are still very clear, but do contain inclusions only trained gemologists can find under 10x zoom. The main difference between VVS1 and VVS2 diamonds is that one has inclusions visible from the bottom, while the other has them visible from the top. Again, they are only visible under 10x zoom and are very difficult to find (for a skilled grader).

Very Slightly Included (Grade: VS1.

VS1 diamonds are a great choice for most people as they’re more affordable than higher grades, yet still very visibly beautiful. These are “eye-clean” diamonds meaning you can’t see any inclusions with the bare eye.

Very Slightly Included (Grade: VS2.

VS2 diamonds are similar to VS1 diamonds, but the inclusions can be seen with less than 10x zoom. They are easy to spot by a professional using loupes, but they’re still invisible if looking at the stone without magnification.

Slightly Included (Grade: S1.

Slightly included diamonds contain noticeable inclusions, but with S1 diamonds they may or may not be visible to the naked eye.

Slightly Included (Grade: S2.

S2 diamonds have inclusions that are sometimes easier to see without intense magnification. That means they may not be “eye-clean.”

Included (Grade: I1.

Diamonds that are categorized or graded as I have noticeable inclusion in them. They are obvious and may affect the brilliance of the stone. They are usually not “eye-clean” meaning the inclusions and blemishes are visible to the naked eye. Sometimes they are eye-clean, but if you come across an I2 or I3 diamond it will definitely NOT be eye clean.

What Inclusions You Should Always Avoid When Buying Diamonds

In all honesty, some inclusions actually add character to a diamond. But if you’re trying to avoid the ones that are most noticeable/has brilliance affect on diamond, then stay away from long cracks, crystals (specially when they are dark/black), and knots.

You may be thinking because of this, you should only buy diamonds in person but that couldn’t be further from the truth. Technology has truly revolutionized the diamond industry. For instance, many of the best jewelers offer high definition images of the exact diamond you’re considering purchasing.

Not only that, retailers like James Allen offer magnification of up to 40x! Try it out for yourself and you’ll see that buying online actually has more advantages to buying in person.

You also should be examining the diamond certificate, whether buying online or from your local store, GIA adds a clarity section that lists all inclusions & blemishes (for diamonds with +1 carat).

Choosing the Right Diamond Clarity Grade

So what should you be looking for when purchasing a diamond? Of course, everyone would love to only buy purely flawless diamonds, but the price can be so astronomically high that it’s prohibitive.

You know, even if they weren’t extremely expensive, going “insane” in clarity isn’t something you need to, and doesn’t have that direct influence on diamond appearance (unlike the cut for example), usually SI1 & VS2 are great starting point for diamonds around 1 carat since +99% of SI1 diamonds are eye-clean.

For larger diamonds, you might need to consider a higher clarity grade like VS1, but in most cases you won’t need to go this far.

So, it’s established that you don’t need to buy Grade FL or IF stones to have a truly beautiful piece of jewelry. The grade you definitely want to stay away from is I2 and I3 – these are the lowest quality stones and will never be “eye-clean.”

On the other hand, SI grades are much cheaper and are in most cases eye-clean. If you’re doing your shopping with a store that has a large inventory like James Allen or Blue Nile, the chances of you finding a beautiful SI diamond that sparkles is high and almost guaranteed.

About the author

Olivia Bennett is a dynamic and accomplished expert in the diamond industry. With over a decade of experience, she has established herself as a go-to authority for all things diamonds. Olivia's love affair with these exquisite gemstones began in her childhood and has only grown stronger over the years.

Having worked closely with diamond miners, manufacturers, and retailers, Olivia possesses a comprehensive understanding of every aspect of the industry. From diamond grading to sourcing and the latest design trends, her expertise is unparalleled. Clients value her impeccable taste, attention to detail, and personalized approach.

Driven by a passion for education and empowerment, Olivia launched her own website dedicated to diamonds. Through engaging and informative content, she guides individuals through the intricacies of diamond buying, helping them make confident and informed decisions.

Olivia's mission is to ensure that everyone finds their perfect diamond, one that truly reflects their unique desires. With her extensive knowledge and unwavering dedication, Olivia is a trusted guide in the dazzling world of diamonds.