Diamond Inclusion Chart – How it Affects Clarity?

Everyone notices the freckles that some people have as opposed to the conventional birthmarks of others because they are very unique. They are considered to be beautiful and in some quarters sexy. The same cannot, however, be said about certain birthmarks.

In the world of diamonds, birthmarks are considered imperfections that are found on diamonds by reason of the fact that they are formed from deep within the earth’s surface. These imperfections make the diamond unique and one of a kind because none of them are the same.

Freckles, however, would be considered blemishes here because they are imperfections on the outside as opposed to inclusions which are inside. But can they really be graded as imperfections?

What are Diamond Inclusions?

Diamonds are created under tremendous pressure & heat under more than 100 miles on earth, 2000 fahrenheit and more than 70000 pounds per inch square pressure will definitely leave some imperfections on the diamonds surface, these imprefections are called diamonds inclusions.

Diamonds with no inlcusions are very rare, rare to the level that most jewelers (not only customers) live their life without seeing one.

JamesAllen, the biggest online store for diamonds which has more than 309000 diamonds on their website, has only 45 flawless diamonds (diamonds without any inclusions) as you can see here.

Read: What is the Best Diamond Clarity to Get?

Diamond Inclusion

What are Inclusions Types?

All diamonds (except flawless) have inclusions, some of them are clearly visible to naked-eye, while most of them are not, unless you check the diamond with a loupe.

This image for example, found on JamesAllen for around 5k (sold now), has all inclusions types you may ever see, more to come shortly.

Bearing in mind that diamonds possess birthmarks that are unique to each one, inclusions are of different types, let’s take a look at the most popluar inclusion types found on diamonds:

1. Crystals

Crystals are simply put a collection of small diamonds or minerals trapped inside a larger one during formation. Some of them are invisible to an unaided eye. They are of two types, white crystals, and black. It is easy for the white to blend in but you may have a hard time with the black.

Diamond Sparkle James Allen

2. Needle

Needle inclusion in diamondWhen diamonds are formed, the pressure could make crystals turn into a needle-like shapes. They are usually white in color or translucent.

3. Pinpoint

These are inclusions that appear as white dots and are not really visible.

4. Clouds

This is simply a cluster of pinpoints. They are not usually visible but if they are bigger they could affect the gem’s light performance.

5. Twinning Wisp

This inclusion looks like stretch marks but on a gem

It is said to be caused by a pause during formation, the resumption of which leaves the gem dented.

6. Knot

Knot Inclusion in DiamondThese are inclusions that have reached the surface area of the gem. They can actually be seen with naked eyes and they affect the durability of the gem, knot inclusions extends to the surface after fashioning.

Blue Nile Ring 2

7. Feather

Feather inclusion in diamondThis inclusion is called feather because of its shape. It is basically a crack in the inside of a gem. It causes durability issues if placed close to the girdle area, often white and feathery in appearance.

8. Chip

This inclusion is an opening on the edge or surface of the gem. This happens mostly from wear and tear. Chips can be corrected by cutting and reshaping but where they are considerably large, cutting could affect the carat weight of the gem.

9. Cavity

Cavity Inclusion in diamondThis is an angular opening or a hole in the center of a gem,  such inclusions are created when part of a feather breaks away, and sometimes when a crystal that is surface-reaching drops out, they are however not really noticeable.

10. Bruise

This occurs from a blow to the surface of the gem which extends inside. Diamonds are quite fragile hence this inclusion.

So are all inclusions are bad? Not necessarily, actually these inclusions help gemologists separate natural diamonds from synthetics diamonds, as well as identify individual gems and grade it accordingly.

Actually it’s safe to say that each inclusion is quite unique and sometimes beautiful as it adds character to the gem.

The diamond inclusion or clarity chart is basically a grading of diamonds according to their inclusions. This chart was established by Richard Liddicoat and it is called the GIA Clarity Grading System. It is divided into 6 sections:

Diamond Clarity Grades

One of the most important factors in any diamond is the clarity, Clarity is one the 4Cs of diamonds, and it’s graded into 6 categories based on the cleanness of a diamond.

We’ve covered the detailed grades with real images in our Clarity article, but in short here, these grades are:


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

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.

Very Very Slightly Included

Inclusions in diamonds here are difficult to see at 10x magnification. 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 of them, 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.

Very Slightly Included

Inclusions in gems so graded are very visible under 10x magnification but are described as minor. They are not however visible to the naked eye. Their slight inclusions do not affect clarity or transparency. These gems are divided into VSI1 and VSI2.

Slightly Included

Diamonds of this grade have inclusions that are visible under 10x magnification. Some of theses inclusions can be visible to the naked eye when observed under close inspection. They are divided into SI1 and SI2 gems (EGL introduced SI3, but it’s not internationally adopted).


Diamonds of this grade have inclusions that are obvious under 10x magnification. The inclusions are always visible to the naked eye and sometimes may affect the durability of the gem. They also reduce transparency and the brilliance of the gem. They are divided into I1 through I3.

To Which Extent Inclusions Affect Diamonds?

Sometimes gems with inclusions are purchased because the inclusions are the source of beauty in the gem. Most inclusions, however, affect the gem’s clarity or grading, however this could depend on a number of factors:


When gems are graded, the grading comes after the gem has been inspected under 10x magnification. The reason is that the inclusions are mostly visible under magnification. The size of the inclusion impacts greatly on the grading. Where the inclusion is large, the gem is graded lower than where the inclusion is little, and this makes sense, that’s why an eye-clean diamond (VS1 for example) will not have any inclusions that you can see, while the same exact inclusions (if happened) with a larger size will probably make the same diamond an SI1.


When the inclusions in a gem are numerous, it affects the grading as it will make the gem very unattractive.


Diamond TableWhere the inclusion is situated in the gem goes a long way in grading. If it is at the table facet, it is most visible and generally affects how the gem is seen since the table is the like the mirror of the gem and it is the first place considered when looking at a gem. Where it is at the girdle, it is rarely visible. Where the inclusion is at the culet, it reduces the value of the gem because such inclusions can reflect throughout the gem, this image explains how each location affect the overall clarity.


When inclusion is closer to the color of the gem, it lowers its relief. Therefore inclusions like crystal that are translucent or white have less impact on the gem than inclusions that are dark.


Different types of inclusions that we mentioned previously have different degrees of impact on a gem’s clarity and grading. For example, pinpoints have a lesser impact because they are barely visible even under 10x magnification. Other inclusions like feathers can have a greater impact as it could cause gems to crack.

Final Word on Diamonds Inclusions

The inclusions in a gem can only be visible where the gem is loose. When it is in its setting, grading may be difficult because the prongs or the bezel may hide the inclusion. This could also be a good thing when gems with inclusions are purchased. The inclusions could be made to hide in plain sight with the chosen setting.

Whereas the freckles as stated above add beauty and are considered unique characteristics of an individual, they do not impact on the value attached to such person. Diamonds are however inanimate and are assessed based on the idea that they should, in fact, be perfect.


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