Summary in a few lines:

Diamonds inclusions are small imperfections in diamonds, happen as a result of extreme heat & pressure the diamond get when formed.

Inclusions aren’t necessary bad, most of them are “okay” to be in a diamond depending on size & location, but some are NO-GO and indeed should be avoided.

Look at this stunning 1.1 H SI1 diamond on James Allen for example, although it has 4 inclusion types as listed on its GIA certificate, it’s eye clean, looks great, and will definitely be an amazing pick:

1.1 H SI1 Ideal

Diamonds with no inclusions are very rare, on James Allen, out of 552k diamonds, only 7k are flawless or internally flawless (flawless only are even lower, 250) as you can see in this search (less than 1.5%), the same (almost) goes for Blue Nile, with 10k out of 510k diamonds!

In short: The worst clarity characteristics (inclusions) to be avoided are Black carbon spots/crystals, Long fracture/cracks, Knots, Clouds, and in terms of position: inclusions in the diamond table center.

What are Diamond Inclusions & Blemishes?

In the world of diamonds, birthmarks are considered imperfections (inclusions) that are found on diamonds, for the sole reason that they are formed under intense conditions.

827X827 THLD23

Under 100 miles deep, and a 2,000 Fahrenheit temperature (around 1100°C), with an exerted pressure of more than 70,000 pounds per inch square (too much physics!), a diamond with some flaws (on its surface) will definitely be made! 

These imperfections are called “Diamond Inclusions”.

Pro Tip: Generally, it’s common to refer to any imperfection on the diamond as “inclusion”, while there is a main difference between inclusions & blemishes.

Pro Tip 2: Some people “mistakenly” type it as occlusion rather than inclusion, that term is completely wrong here and belongs mainly to the dentistry industry.

Inclusions are these birthmarks which are internal (haven’t reached the diamond surface), while blemishes are -obviously- external birthmarks (on diamond surface).

These imperfections cause the diamond to be unique and one of a kind because none of them is completely identical!

How Inclusions Look Like?

As a matter of fact, there are many diamond inclusion types. For instance, the image you see here is for a diamond with an SI2 clarity grade on “Blue Nile”, that diamond actually has 6 diamond inclusion types!

We’re not saying 6 inclusions, no it has 6 different types of inclusions:

Diamond with a lot of inclusions on Blue Nile

If you take a look at the GIA certificate of that diamond, and in particular its clarity section, what you’ll see is a clear representation of all clarity inclusions found on the diamond, their locations, and types!

SI2 Diamond GIA Cert Clarity Section

A valid question here: Is this a diamond that I should pick or avoid?

Well, it’s 1.5 carats and considerably cheap for that carat & an excellent cut, but with all these visible inclusions, we don’t think so!

Hmm, you mean I should always look for a flawless/internally-flawless diamond?!

Definitely no, actually we always recommend to start with SI1 clarity for most cases.

Want to see how a diamond with clear clarity looks like without going insane in clarity grade?

Say no more!

Check this diamond on James Allen’s site, looks way better! And it’s just VS2 graded, this is 20x magnification of the diamond:

VS2 on James Allen

And here is its clarity section from the GIA certificate:

GIA 1.08

Huge difference, right?

That diamond has a VS2 clarity grade, which is just one grade higher than SI1!

You see the value of getting & checking the diamond certificate before proceeding with the purchase! And make sure that the certificate is from high-reliable labs like GIA.

That’s why we always considering James Allen, Blue Nile or Whiteflash when you’re getting a diamond, they provide diamonds certification on spot for any diamond you want.

Whiteflash 360 HD Diamond Videos 970x250 1

Diamond Inclusion Types

Based on the shape and structure, certain names have been given to the diamond inclusions, and of course, some should be avoided more than others!

Let’s start:

1. Crystals

Crystals inclusions are basically a collection of small diamonds or minerals trapped inside a larger one during formation. They can either resemble a diamond within a diamond or can resemble bubbles.

They appear in many colors: White, black, colored, and sometimes even transparent (colorless) crystals. Some of them are so tiny they’re invisible to the unaided eye.

It is easy for the white to blend in, however, the black and the transparent will definitely be popping out! The darker the color, the more you need to avoid; since it will have more effect on the diamond’s brilliance.

A rule of thumb would be to try to avoid any and all colored crystal inclusions.

Here is a diamond from Blue Nile with a crystal inclusion on its table facet:

Diamond with crystal inclusion

2. Needle

This would be one of the most common diamond inclusion types that you’ll see while shopping for your stone! Needle inclusions are usually seen under magnification as it’s not easy to detect them with the naked eye. 

When diamonds are formed, the pressure could transform crystals into needle-like shapes (clustery). They usually have a white color or just transparent.

Blue Nile Ring 2

Despite the fact that diamonds are the strongest stone on earth, long and deep needle inclusions can (and will) weaken your gem; making it more vulnerable and less-harder to break! 

Here is a diamond with many needles. You can notice that they’re pretty hard to spot.

Also, check out this diamond; which has a clearer needle on the table facet. Keep in mind that this is a 20x magnified image and that this inclusion is most probably not visible to the naked eye:

Diamond with needle inclusion - James Allen

In most cases, needles are okay in diamonds, you shouldn’t worry about them as long they are not too deep or too long.

3. Pinpoint

These are very tiny inclusions and can barely be seen under magnification. They appear as white dots and can be either white or black. This inclusion is considered diamond-friendly and doesn’t have much effect on diamond clarity.

The image here shows a pinpoint:

Pinpoint inclusion on diamond - Blue Nile

As you can see, it’s very small and won’t have “almost” any effect on the diamond, it’s safe to get diamond with such tiny pinpoints.

4. Clouds

Clouds are sometimes referred to as a group (cluster) of pinpoints or crystals. It’s called a cloud when these pinpoints are very close to each other so that they form a “cloud” of inclusions.

They are not usually visible, however, if they are bigger, they might start to appear a bit cloudy or hazy; affecting the appearance of the stone and its light performance (therefore its sparkle!)

This diamond has 4 clouds on its table & crown facets, they might not be easily located before taking a look at the GIA certificate:

Diamond Cloud

5. Twinning Wisp

Usually, the twinning wisps are found in fancy-shaped diamonds. The larger the-wisp, the lower the clarity.

A Twinning wisp looks a lot like stretch marks on a gem. It’s a bit different from the cloud inclusion in that it’s a series rather than a group of pinpoints/crystals (it even can be a series of clouds as well).

It’s been said that is caused by a pause during diamond formation and the resumption of which leaves the gem dented.

Here is a diamond with 4 twinning wisps on Blue Nile.

Diamond with twinning wisps inclusions

Generally speaking, what applies to clouds applies to twinning wisps as well, if they are large, it’s generally recommended to be avoided.

6. Knot

This is a definite NO when it comes to diamond inclusion types! 

Knots can actually be seen with naked eyes and they affect the durability of the gem. These are inclusions that have reached the surface area of the gem. It’s also worth mentioning that knot blemishes extend to the surface after fashioning.

Knot Inclusion in Diamond

7. Feather

This inclusion is named after its shape. It is basically an internal crack inside the gem. If the crack is located cleanse to the girdle area, it could cause serious durability issues!

You may also like:  The Unspoken Truth of Diamonds: Blood & Conflict Diamonds

It’s better to be avoided if it’s large in size or reached the surface. Affecting the diamond clarity is not the big issue here!

Feather inclusion in diamond

Feathers are often white and feathery (hence the name) in appearance. This diamond on Whiteflash has two feathers right in the middle of its table, a bit to the left:

Diamond with feather inclusion Whiteflash

8. Chip

An opening on the edge or the surface of the gem; caused mostly by the wear and tear of the ring. Chips can be regulated by cutting and reshaping. However, in case the chip is considerably large, cutting could affect the carat (weight) of the gem.

This type of inclusion is less common to be seen since most of it can be treated in diamond cutting process, and if any, it won’t have much harm to the diamond appearance & brilliance.

9. Cavity

This is an angular opening/hole in the center of the stone. Such inclusions are created when part of a feather breaks away, and sometimes when a part of a surface-reaching crystal drops out. However, cavities are rarely noticeable.

Cavity Inclusion in diamond

10. Bruise

A blow to the surface of the gem leaves bruises that extend inside. Diamonds are quite fragile in spite of this inclusion.

Bruise inclusion is less common among diamonds, and probably you won’t come across one while shopping for your diamond, but still, if you find a diamond with a bruise, watch out for visible/large ones; because it’s that type of inclusion you want to avoid in your diamond.

11. Bearding

Beard-hair inclusions (known as bearding) often occur in the cutting stage of the diamond. Whilst it can be ignored when tiny, it sure can’t be overlooked if the girdle is heavily bearded! 

Its appearance will look grey and fuzzy fringe, almost as if it has been scratched. Not a good look on a diamond!

12. Indented Natural

Last but not least, the portion of the rough diamond’s original surface which can’t be fixed with the polish (since it dips below a polished diamond’s surface) is called “Intended Natural”.

Indented Natural

This diamond on Blue Nile has 3 indented natural diamonds as you will see in the certificate. These inclusions are extremely tiny that they’re almost invisible even under 20x magnification, so generally-speaking, intended natural inclusions are okay to be in a diamond.

JamesAllen Promo

These are the main inclusions types that you might come across while browsing for your diamond. Just looking at the diamond itself isn’t enough. You MUST read the certificate to understand what types of inclusions the diamond has and how they affect its clarity!

Pro Tip: The clarity section in the GIA certificate is only available for diamonds with 1 carat and above. We’re mentioning this so that you won’t be surprised if you don’t see a clarity section in your GIA certificate!

What Diamonds Inclusion You Should Avoid

Whether you call it an inclusion, a blemish, or clarity characteristics, there are certain types of these imperfections that you should be very careful when they are present in the diamond.

As each of the 12 different inclusion types we mentioned above is different, their effect on diamonds ability to reflect light, appearance, and even durability varies.

In a nutshell, here are the worst inclusions to be avoided, graded with No.1 being the worst:

1. Black Carbon Spots / Crystals:

The light passing through the stone will be literally blocked (in the exact spot of the black crystal). These inclusions will look like tiny pieces of crushed black pepper.

These are the worst inclusions; you better avoid them whenever found, on or underneath the surface of your diamond for that matter. 

Remark: Note that we are only talking about black-colored crystals.

2. Top / Center-Located Inclusions:

Generally speaking, any notable inclusion located on the top or in the center is quite harmful to your gem!

Look at this diamond on James Allen’s and check out the inclusion located in the middle.

This location specifically is such a killer of a diamond’s brilliance. (This diamond has many other visible inclusions as well, but we wanted to highlight how important the location of inclusion is).

James Allen Diamond with inclusion in center

Whenever you’re looking for a diamond, just try your best to get a clean top-surface diamond (diamond table).

3. Long Fracture / Crack:

Have you ever imagined that a diamond is breakable? What about the 10/10 grade of strength on the Mohs Scale of mineral hardness?

The diamond has a short needle? Not a big deal. However, a long/deep needle/crack is a serious issue; as it runs all the way through the diamond! 

Slamming such diamond to a wall too hard might also crack it (or even split it into halves!). It’s rare and totally dependent on the crack depth and length as well.

If you look right through this diamond; 6 o’clock sharp, you can clearly see a long crack. Not too long to break a diamond, but definitely an inclusion you’d want to avoid!

4. Clouds:

Back to our clouds! Small clouds? Those we can ignore. It’s the cloud covering a big portion of the diamond’s surface that we can’t!

By leaving the diamond looking hazy and milky, clouds affect the look, and more importantly, the brilliance of a gem.

Look at this diamond in 360-degree on the Blue Nile. Also, a screenshot of its clarity section on its GIA certificate as well:

Cloud on Center of a Diamond

It’s not only that the cloud is covering a lot of space on the diamond surface, what’s worse is the location, right in the middle of the table facet.

5. Knot

It’s always a NO-GO when the diamond has a knot inclusion, it can really get worse by time so even if it minor, it might be more visible by time.

Inclusions Characteristics Effect on Clarity Grading

By now, we know for a fact that not all inclusions are equal, but beside the type, what are other factors that should be taken into consideration when assessing an inclusion?

Look at these two diamonds on Blue Nile and their clarity section in the image after:

1- 1.00 Round, F Color, SI1

2- 1.01 Round, I Color, SI1

Diamond Clarity Difference on GIA

And particularly on diamond 1 lower girdle facet (bottom right at 5 o’clock), you will see there is a small inclusion there, and on the keys section, it will tell you that this inclusion is Cavity.

This inclusion type & location degrades the clarity and the grade of the stone to SI1, but it’s not the only factor causing this step down!

The inclusions found on the very first image to the left (crown of the 1st diamond) are located at the worst location in a diamond (look again here using 360-degree, it’s easily visible).

In many cases, they will be seen by naked-eye, and more importantly, they hugely affect the diamond’s brilliance since light passes through the crown first.

The first one has around 9 “tiny” inclusions on its crown, and this is “relatively” a low number of inclusions, yet it was graded as SI1 not higher!

The second one has tons of inclusions all over its crown! And it was graded SI1, the same as the first one. Why is that?

Basically, because each inclusion impacts the gem differently. As we said before, no two inclusions are identical. Some can really harm the diamond’s brilliance; messing up its ability to reflect the light, others don’t.

Here are the main factors for how a clarity characteristic/inclusion can affect diamond clarity grade: 

1. Size

First comes the inspection (under 10x magnification; since inclusions are mostly visible under magnification), then comes the grading of the gems. The size of the inclusion has a huge impact on the grading.

Larger inclusions lead to lower grading, and vice versa. This totally makes sense actually, since eye-clean diamond (VS2 for example) will not have any inclusions that you can see, whereas the same exact inclusions (if existed) with a larger size will probably make the same diamond an SI1.

2. Number

Numerous inclusions in a gem leave it unattractive as well as affecting its grading.

3. Relief

Low relief means that the inclusion’s color is close to the stone’s color. Therefore, inclusions like crystals that are translucent or white have less impact on the gem than dark ones.

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4. Type

Various types of inclusions impact the clarity and the grading of a gem in various degrees. For instance, pinpoints have a lesser impact because they are barely visible (even under 10x magnification). Other inclusions like feathers can have a greater impact as they could cause a gem to crack.

5. Location

The location of the inclusion matters! Where the inclusion is situated in the gem goes a long way in grading, look at this image for example:

Diamond Table

If an inclusion is at the table facet, it is the most visible of all and generally affects how the gem is seen (since the table facet is like the mirror of the gem), also it is the first place considered when looking at a gem.

When located at the girdle, it is rarely visible. Inclusions at the culet are another story! They reduce the value of the gem tremendously given that they can reflect throughout the whole gem.

In a nutshell, inclusion location is very important to determine clarity grade and overall brilliance, always look for a diamond with less or no inclusions on the top, or on the girdle (and its upper/lower facets).

Quick Overview of Clarity Table

Clarity is one of the 4Cs of diamonds and considered one of the main pillars in specifying a diamond worth. In GIA standards, clarity is graded into 6 categories based on the cleanness of a diamond.


We’ve covered the detailed grades with real images in our Diamond Clarity Chart, but for the sake of summarizing, we’ll mention the grades below:

1. Flawless

Diamonds graded FL have no visible inclusions or blemishes to the eye at 10x magnification. These diamonds are extremely rare and are very expensive. Only 1 in 5000 diamonds are rated flawless.

2. Internally Flawless

These are diamonds that do not have inclusions but only blemishes. These blemishes are barely visible under 10x magnification. Only about 3% of diamonds are ever rated IF and if put side by side with FL, they are quite similar to the unskilled eye.

3. Very Very Slightly Included

Even at a 10x magnification, inclusions in diamonds here are still difficult to see. For VVS1, inclusions can only be seen from the pavilion while for VVS2 diamonds, their inclusions can only be seen from the crown.

For both, the inclusions are of course not visible to the naked eye and look similar to the flawless grades. These diamonds have clarity and are equally expensive.

4. Very Slightly Included

These are considered minor inclusions. They are very visible under 10x magnification, however, they’re not visible to the naked eye. Their slight inclusions do not affect the clarity or the transparency. These gems are categorized into VSI1 and VSI2.

5. Slightly Included

This grade contains diamonds having visible inclusions under 10x magnification. Some of them are also visible to the naked eye when examined under close inspection. They are divided into SI1 and SI2 gems (EGL introduced SI3, but it’s not internationally adopted).

Feel free to read our EGL vs. GIA comparison guide if you ever thought about getting an EGL diamond.

6. Included

Diamonds under this grade have inclusions that are obvious under 10x magnification. The inclusions are always visible to the naked eye and might even affect the durability of the gem. They also reduce transparency and the brilliance of the gem. They are divided into I1 through I3, don’t ever get any of them!

You can also read: What is the Best Budget-Friendly Diamond Clarity?

1 Carat Diamond Price for Different Clarity Grades

After all that’s been said, it would be safe to mention how these inclusions (which define the clarity grade for any diamond) affect diamond pricing.

Comparing an apple to an apple, we will be freezing our search to these characteristics, and then see how changing the clarity level affects the pricing in each!

Cut: Excellent

Carat: 1

Color: G

Polish & Symmetry: Excellent

Fluorescence: None

Shape: Round

Certificate: GIA

We will use our favourite online store James Allen as a price reference; as it has one of the largest diamond inventory and more than 500,000 unique options for diamonds!

JamesAllen Promo

Regardless of how much money you have and find reasonable for the price of your ring, we recommend shop diamonds online and definitely believe it’s a responsible decision! The savings are incredible and the quality is great. You can check one of our favorite online stores: James Allen, Blue Nile, and Whiteflash.

1 Carat SI2 Clarity Price Range

After running a search on James Allen’s with the above-mentioned characteristics, the result was 400 diamonds, with prices ranging between $2.9k and $5.9k.

1 Carat SI1 Clarity Price Range

This search on James Allen’s with the above-predefined filters resulted in 311 diamonds, ranging between $4.8k to $7.4k.

Note the huge increase in price (for just one grade in clarity). That’s simply because SI2 is not eye-clean in most cases, while SI1 is the exact opposite, eye-clean in most cases.

That’s why we always start your clarity search from SI1 since it’s good enough for almost everyone.

1 Carat VS2 Clarity Price Range

A similar search here, returned 309 diamonds, from $5.9k to $8.2k.

Again, a huge increase in price. Think about it for a second, people resort to VS2 to stay safe in terms of visible inclusions; since it’s 100% eye clean.

1 Carat VS1 Clarity Price Range

We got 234 diamonds, prices varied between $7.3k and $9.1k.

1 Carat VVS2 Clarity Price Range

183 diamonds, with a price range of $7.6k and $9.3k.

1 Carat VVS1 Clarity Price Range

81 diamonds, ranging between $8.7k and $10k.

Going to FL & IF would be insane, see how much difference people are paying for something that has no major effect on diamond? Go to VS2 and your diamond will be great, why paying $5k more for something a salesperson have said?


When you’re set on getting your diamond, watch out for the inclusions. Nonetheless, keep in mind that inclusions can only be visible where the gem is loose. 

However, when the gem is in its setting (mounting style on the ring; holding it in place), grading might be difficult; since the setting (prongs or bezel) might be covering the inclusions somehow!

This could also be a good thing when deciding to purchase a gem with inclusions. The setting could be made to hide the inclusion 😉


Still not sure where to buy your diamond?

We always recommend shopping diamonds online and created a Full guide to shop diamonds like a Pro.

Among online retailers, here are our favorite stores (click their logo to visit store):

1) James Allen: Our favorite online store, best diamond imaging technology available today, comes with the largest collection with more than half a million loose diamonds.

Latest JA Logo2) Blue Nile: Widest collection of loose diamonds of all sizes, great imaging technology for most of their  inventory (hundreds of thousands of diamonds), great customer support.

Blue Nile Latest Logo

3) Whiteflash: Home Of A CUT ABOVE® Super Ideal Diamonds, they stand out from the crowd by offering premium diamonds cuts, tailored to those who love the details, at great prices too.

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About the Author

Christopher Morgan

Christopher Morgan is a talented wordsmith with a passion for diamonds and a flair for storytelling. With a unique perspective on the industry, Christopher brings a fresh voice and captivating narratives to his writing.

Having been captivated by the brilliance of diamonds from an early age, Christopher immersed himself in the world of gemstones. His extensive research and experience have given him a deep understanding of the diamond industry, from mining and cutting to the cultural significance of these precious gems.

Christopher's engaging writing style and ability to blend technical knowledge with artistic expression make his articles a delight to read. Through his work, he aims to inspire readers and ignite their curiosity about the fascinating world of diamonds.