Types of Diamond Inclusions

Types of Diamond Inclusions

Do you know the different types of diamond inclusions? Read on for 15 diamond inclusion types you should be aware of.

Have you always wanted to know the kinds of inclusions found in diamonds?

You have landed on the right site; here we shall let you in on diamond inclusion types and other things like:

  • The main 5 types of diamond inclusions
  • Spotting diamond inclusions with the naked eye
  • Are diamond blemishes bad?
  • Can you buy a diamond that has inclusions?
  • And a lot more!

diamond inclusions

What are Diamond Inclusions?

The immense pressure and above the ceiling temperatures found deep inside the earth’s mantle are responsible for the inclusions that are found in diamonds. Diamond crystals normally have different clarity characteristics found on and in the stone.

There are handful of diamond crystals that do not have inclusions on the inside or outside. In jewelry stores, you will find such diamond grade referred to as flawless clarity. This lies on the E rating on the clarity scale.

Lab-grown diamonds always have inclusions too, although made using metallic rather than mineral crystals. This is the basic way that jewelers can differentiate a natural and a lab-created diamond.

Blue Nile Diamond Clarity Image

Are Diamond Inclusions Good Or Bad?

Diamond inclusions are neither good nor bad; in fact, they are the unique identifier of your diamond. There will be no other diamond with inclusions similar to yours, even if it is created in the lab.

In addition, it is more appealing to group diamonds according to their level of clarity such that there are diamonds that are more desirable than others are. The best diamonds, with the least inclusions and considered more desirable are internally flawless diamonds or flawless. However, there is no justifiable reason to spend a fortune.

If you desire an eye-clean diamond, check out the tips and tricks we wrote to find out the best and cheapest way to get your dream piece of diamond jewelry, without spending an extra cent for perfection.

It is important that you know and understand a diamond’s anatomy so that you can understand its inclusions and how it affects the diamond’s appearance.

For starters, a diamond’s body has two parts. The half part on the top is called the crown and the lower half is the pavilion. The crown consists of the table and girdle. The table refers to the part that you look at when facing the diamond from the top as if the diamond sits in a setting. The crown has several facets, which are in most cases cut into brilliant facets. The girdle is the outer edge of the diamond and goes round the shape of the stone.

The pavilion of a diamond is the cone-shaped section, commonly in a round cut diamond. Like the crown, the pavilion has long facets, which run to the bottom and are referred to as the culet. However, not all diamonds cuts have a culet or even shorter facets.

The question of whether to worry about inclusions on your diamond depends on the diamond inclusion types and location. Very few inclusions can be noticed if located on the girdle, but become more conspicuous if positioned in the pavilion. This is the sole reason you should be familiar with the anatomy of a diamond.

anatomy of a diamond

Types of Diamond Inclusions

So many types of diamond inclusions exist that you cannot quickly rush to label one as bad. Aside from the numerous kinds of inclusions, these blemishes differ in location and size. As such, no particular kind of inclusion can look bad on one diamond, but good on the other.

Almost all mined diamonds have natural blemishes that can be viewed using a 10X magnifier. Below are the different diamond inclusion types found in real diamonds.

anatomy of a diamond

Crystal Inclusion

A crystal inclusion is not anything different from how it sounds. Basically, mineral crystals are trapped in the diamond during the formation process. This is the commonest kind of inclusion. A crystal inclusion can be colorless or colored depending on the kind of mineral that was trapped.

Colored crystal inclusions may appear greenish if peridot is trapped, black from carbon crystals, or reddish when garnet is trapped. Black inclusions are the most common. It is rare to come across a diamond that has red or green blemishes since these are considered low-grade and not sellable.

Crystal inclusions are very common in diamonds with clarity grades VS2 or lower. Most I1 diamonds you find in the market have several crystal inclusions. Crystal inclusions are normally too small to be seen, so you should be concerned more about the jewelry’s appearance than its durability. You need to avoid big black crystal inclusions.

carat round diamond
1.00 Carat Round Diamond

Pinpoint Inclusion

Pinpoint inclusions are common and can be noticed as minute black or white dots in the diamond, but it is mostly white. The dot-like inclusions result from very small crystals of minerals that were trapped in the diamond.

Pinpoint inclusions are common in diamonds with high clarity grades such as VS diamonds. With a 20X magnifier, you can see pinpoint inclusions, they are not visible with the naked eyes.

VS diamonds normally have white pinpoints. These kinds of inclusions are very difficult to tell their exact location; hence, you will not find them plotted on a grading report. The report will only indicate that there are pinpoints in the diamond but with no specific locations.

Because of their size, pinpoints do not have a negative impact on the diamond’s appearance; therefore, you need not worry about brilliance and shine. Something worth noting is that more pinpoints can team up to form another kind of inclusion.

Needle Inclusion

If you love or have seen colored gemstones more than a few times, you probably have already seen needle inclusions. Needle inclusions are usually long, thin, and white. Many gemstone lovers like these kinds of inclusion. Watch the video below to get more details.

These inclusions look very appealing in quartz stones but the reverse is true for diamonds. A diamond that has as many inclusions as that would never see the light of day in the market, but if the inclusions are small, they can be sold.

These inclusions are too thin and small to see with the human eye only. A 10x magnifier would come in handy to see these inclusions. These blemishes do not affect the diamond when viewed from the face unless they are in clusters. Eye-clean diamonds like VVS diamonds are not likely to have these issues.

A forward slash plotted on a grading report indicates that the diamond has needle inclusions.

1.01 Carat round diamond
1.00 Carat Round Diamond

Twinning Wisps Inclusion

A twinning wisp inclusion is formed when other diamond inclusion types come together. For example, when pinpoints, clouds, or crystals group into one, a twinning wasp is created. This inclusion is normally created in natural diamonds during formation.

Sometimes, a diamond may stop growing when conditions inside the earth become unfavorable. Once the conditions become favorable again, the diamond continues to grow. When the growth process restarts, the inclusions continue to grow too, but in a different direction, hence the creation of tiny wisps. All diamond shapes apart from the round are formed from twinned crystals. This means twinning wisps inclusions are more familiar with diamonds that have a low clarity grade.

Feather Inclusion

Who does not love feather inclusions? They are very beautiful. Feathers are very unique characteristics that compliment the appearance of the diamond. Feather inclusions are created when the diamond has a crack. Any small fracture on the diamond can cause the feathers to form.

Feathers are everyone’s favorite since they are neatly positioned to look like the white feathers of a bird. However, you need to be cautious of where these inclusions are positioned. Diamonds that have these inclusions near the girdle or next to other cavity inclusions make the diamond less durable. If the diamond is knocked on that area, it puts the diamond at risk of chipping.

Feather inclusions can be seen both by the naked eye and under a 10x magnifier, but this depends on other diamond characteristics, most especially the clarity grade. AGS and GIA plot feather inclusions as diagonal squiggle that stretches from right to left.

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Internal graining

Have you ever seen a diamond that has faint white lines that move to the same direction? If so, then you have seen a diamond with internal graining. The pattern looks like straight lines that have been grazed on the side. This type of inclusion comes about when a diamond does not grow regularly deep inside the earth.

Looking at internal graining, you will see that it looks like faint smooth lines. Diamonds that have more intense internal graining always make the diamond look like it has creases and is more reflective. Poor quality diamonds have colored internal graining.

The smooth lines are referred to as grain centers if they resemble threads that go in different directions. In most diamonds with internal graining, the lines appear more on the pavilion and do not affect the diamond’s appearance. The inclusions become more visible if located on the diamond’s table.

On the grading report, the diamond plot will have a dashed squiggly line that runs from the bottom left to the top right. However, diamond internal graining inclusion is normally covered in detail in the comments section of the report rather than the plot.

1.01 Carat round diamond

Cloud Inclusion

Remember pinpoint inclusions? Well, when three of such are located in the same area, cloud inclusion is formed. Cloud inclusions are white and have a misty or foggy appearance. Cloud inclusions look more like what you would see when wisps of smoke are in the air. It does not look like the clouds we see in the sky.

The number of pinpoint inclusions within a cluster determines how big or small a cloud inclusion can be. These inclusions are commonly found in SI1 or SI2 diamonds or those with lower clarity grades. Cloud inclusions do not interfere with the diamond’s durability. VS1 diamonds do not have clouds that cab ne seen without magnification.

If there are many pinpoints in a cluster, then the cloud can be seen with the naked eye. The clouds found deep in the stone have less visual effect on the stone than those at the surface. Diamond laboratories use a dotted circle to indicate a cloud inclusion on the diamond plot.

Indented Natural

As the name sounds, an indented natural inclusion refers to a natural indent in the diamond. It is normally indicated by a tiny unpolished area near the diamond’s girdle. In most cases, the jeweler realizes he cannot cut the indent without sacrificing the carat weight

The good news is this is not the type of inclusion to worry about. As long as it is not large or pronounced, it should not be anything of concern. In fact, it helps you envision how the diamond looked before polishing.

The video below shows you the symbol that graders use to indicate an indented natural inclusion on the diamond plot.

Diamond Inclusions to Avoid

Knot Inclusion

A knot inclusion is a kind of crystal inclusion that goes up to the surface of a polished diamond. When you look at a knot using a magnifier, you will notice that it looks like a bulge on the facet.

It is not easy to find knots in diamonds that are clean to the eye. However, you will see much of them in SI1, SI2 and I grade diamonds. You can clearly see these inclusions with the naked eye.

When buying diamonds, stay away from diamonds that have inclusions on the surface like knots. You may not see the negative impact soon, but rest assured that the diamond’s durability is at stake and you will realize that in the end. Inclusions found on the surface put your diamond at risk of cracking and chipping. Look out for a green oval outline on the grading report to identify a knot. The outline faces east to west and has is fitted with a red oval on the inside.

Cavity Inclusion

Think of the cavities in the mouth, diamonds can have that too. A cavity is a small opening on the face of the diamond. However, this opening is too small to be visible to the naked eye.

A cavity inclusion comes to be when an internal inclusion such as a mineral crystal falls out. The hole left behind after the crystal falls is the cavity. It is a little hard to see cavity inclusions that are near the girdle or in the crown. The ones found in the pavilion or bottom of the diamond are more visible.

While cavities do not harm your diamond in any way, they come with clarity issues. Cavity inclusions make it hard to clean diamonds since oils and dirt is trapped in the holes turning them black. Trying to clean the stained hole with a smooth brush can prove to be a daunting task. You need to keep this in mind if you are thinking of buying a diamond with cavity inclusions.

A green oval moving from east to west featuring red diagonal lines on the inside is used to indicate these inclusions on the diamond report.

Chip Inclusion

A chip is an opening on any part of the diamond. Most chips are located near the girdle or culet. Certain diamond shapes have chips on the bottom. A chip is considered a blemish as well.

A chip normally occurs when the diamond is knocked hard on something. The stone could be knocked on the edge of a wall, countertop, frame, etc. The good news is there is something you can do to reduce the likelihood of your diamond chipping. The basic is to buy a diamond ring that does not have sharp ends, especially shapes like pear cut or marquise.

Diamonds that have small chips are usually marked with the ˄ symbol on the grading report. Diamonds with small chips are nothing to worry about, as the diamond can be re-cut to remove the chip. Re-cutting large chips lead to loss of carat weight.

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Etch Channel

There seems to be confusion or misunderstanding as to whether an etch channel is a natural diamond inclusion or manmade. Gemologists seem to lean more on the thought that etch channel is a natural characteristic in diamonds that happens during growth.

You will be forgiven to mistake a laser drill hole for an etch channel. The etch channel does some things that a drill hole does not. Both look like a deep tunnel, but the etch channel has parallel lines. Etch channel inclusions come about because of the conditions that the diamond forms in. the high pressure and heat cause the diamond to scar, thereby leaving an etch channel inclusion.

Etch channels do not affect the durability of a diamond but make it hard to clean. Similar to drill holes and cavities they trap oils and dirt that turn them black. This impacts the clarity grade of the diamond, especially if the blemish is positioned in the pavilion.

The etch channel is represented by a red rectangle with a slightly smaller green rectangle on the inside of the diamond plot.

Types of Manmade Inclusions

When you hear people talk about diamond inclusions, they simply refer to the characteristics that happen to the diamond throughout its formation process. However, there are inclusions that are unintended jeweler actions in an effort to enhance clarity. They can also be as a result of an accident when cutting diamonds.


Bearding normally happens on the diamond’s girdle. It can also be visible on the edge of the top and all way around the diamond. Diamond grading reports always indicate bearding as Thin to Very Thin, Medium, or Slightly Thick to Very Thick among others.

The girdle of a diamond with bearding appears blurry or whitish. Bearding is a result of poor cutting or polishing. All these are not natural occurrences. Bearding happens to a diamond over time but it is not common.

The blurry edge of the girdle is made of many tiny feather inclusions. You might be wondering whether a bearded diamond is good or a deal-breaker. This depends on how thick the girdle is. While bearding does not affect the diamond negatively in most cases, it can be an issue if the girdle is Very Thick. The inclusions cover a large portion of the diamond making it appear unattractive.

Most bearding inclusions are only visible under a jeweler’s gemscope. Diamond reports do not have a bearding plot, but all you need to know about this inclusion is found in the comments section.

Internal Laser Drilling

When a diamond’s clarity is enhanced using a laser drill, it ends up with a laser drill hole inclusion. The holes are, however, not as big as you may be imagining, especially if you know how the procedure is done.

The laser frills create very thin holes on the diamond, as this is a hair strand. The holes make their way to inclusion inside to dissolve the inclusion using melting heat or acid. Laser drilling is not common in diamonds and jewelers are mandated to tell the customer if the diamond has undergone laser drilling.

In the past, Federal Trade Commission did not require laser drilling to be disclosed because the procedure did not affect the visual aspect of the diamond negatively. The diamond sellers have always made this known to the customers, but now, even FTC supports them.

SI1 and SI2 clarity diamonds are known to have internal laser drilling. Diamonds with these clarity grades have few visible blemishes. A diamond that has not undergone this procedure may be graded as I1. Clarity enhancement via laser drilling is not necessary in VS1 and VS2 diamonds since they are eye-clean.


When you hear someone talk about a bruise, the most likely thing that comes to your mind is a soft surface such as a fruit or human skin. Diamonds are fragile, especially when enormous pressure is applied to them. Therefore, they too can get bruises. A great force on the diamond creates many small feather inclusions to form.

Most bruises are caused by the cutter, who may not be attentive when working on the diamond. Bruises are created when the jeweler uses diamond-cutting machines such as a polishing wheel. When this machine is pressed so hard on the diamond, it causes bruises.

Look out for bruises on the crown facets of the diamond, this is the part on top and has the facets that face up. A small x on the grading report represents a bruise.

Metallic inclusions

Unlike other diamond inclusion types, metallic inclusions are only found in lab-grown diamonds. Lab-grown diamonds are authentic diamonds put into chambers that mimic underground conditions. Scientists can create diamonds in the laboratory in several weeks instead of the billions it takes for diamonds to grow deep in the earth’s mantle.

Metallic inclusions naturally occur in synthetic diamonds but do not happen in real diamonds. These inclusions cannot be seen with the naked eye and cause no harm to the diamond. Because of this, there are no I clarity synthetic diamonds. All lab-created diamonds should be eye-clean.

Can You Buy a Diamond with Inclusions?

That a diamond has a blemish, two, or three does not mean that it is not worth buying. Some inclusions and dark and not appealing while the majority are minor and will not have an impact on the diamond appearance or the stone’s integrity.

The great advantage of buying diamonds on the internet is that their prices have been reduced by about 40% compared to those in physical stores. This means you can find an eye-clean diamond with a high clarity grade for much less than you would in a store downtown.

Most inclusions, whether natural or manmade are not something to worry about and depend on personal preference. You should always aim at buying diamonds from a retail store that lets you view the diamond in 360 degree, or a microscope. Doing this will help you avoid inclusions that will affect your diamond’s appearance.

Should you buy a diamond with inclusions? If your budget allows, let the inclusions go and buy a diamond that is eye clean such as I1 diamond. If your budget is a little constrained, there is no harm in buying a diamond that has inclusions.

The decision is yours.

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