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Diamond Inclusions: What Are Inclusions In Diamonds?

Diamond Inclusions: What Are Inclusions In Diamonds?

If you have started searching for the perfect diamond, you’ll most likely come across the term “inclusions.” If you’ve found the ideal cut and color for your gem, the final obstacle between you and the perfect sparkle is inclusions. 

So, what are inclusions in diamonds?

Although seen as flaws, inclusions make each diamond unique. Diamond inclusions take many forms and lead to various impacts. Don’t worry, though – there’s nothing inherently wrong with inclusions. 

However, there are some things about these imperfections you need to take into consideration when purchasing a diamond. In this guide, we’ve covered everything you need to know about diamond inclusions. So, without further ado, let’s dive in.

What Are Diamond Inclusions? 

As you may already know, a flawless diamond is made out of pure carbon atoms arranged in a crystal lattice, and it’s essentially free of any other minerals. But the thing is, nature doesn’t do “flawless.” 

An inclusion, as the name implies, is anything that’s “included” within a diamond.

The range of inclusions that you can find within diamonds is quite large. Small diamonds and other gemstones such as sapphire can be trapped within a bigger diamond, along with other elements and minerals.

Related Read: Diamond Vs. White Sapphire: Comparison Guide

Disruptions or breaks inside the carbon lattice such as graining, twinning wisps, and feathers are also considered inclusions. If visible to a professional at 10x magnification, the mentioned features are defined as inclusions.

Even though not technically considered inclusions, characteristics such as chips and naturals are also essential to understand. Due to them being superficial and not internal to diamonds, such features are classified as “blemishes,” though.

The Most Common Diamond Inclusions

The most common diamond inclusions you’re likely to encounter are clouds, crystals, feathers, graining, twinning wisps, and pinpoints. These are so common that the majority of gems contain just about all of them.

In and out of themselves, there’s nothing inherently wrong with any of these diamond inclusions. The extent to which inclusions should be a concern is determined by how much they affect the durability and beauty of the stone.

The clarity grade assigned by labs provides some indications in this department. 

In the upper clarity grades – especially in VS1 and above – the inclusions are so minuscule that it’s difficult to notice them even without magnification. 

In these higher grades, the type of inclusion is of very little concern. They have no appreciable impact on the beauty and durability of the diamond.

Distinctions become essential in the lower clarity grades. 

Those in the middle – such as VS2 and SI1 – are unlikely to have any negative impact. But they require careful reading of the report issued by the lab and inspection by a trained expert so you can rule out significant issues.

Surface Breaking Inclusions

Inclusions that break the surface include knots, naturals, feathers, cleavages, and chips. In most cases, inclusions and blemishes don’t present problems.

Think about it: The diamond has come up from deep below the Earth’s surface through volcanic eruptions and has endured the extreme heat and pressure of the diamond’s cutter wheel. 

For the most part, diamonds are incredibly durable and can relatively easily endure normal wear in jewelry.

With that being said, surface-breaking inclusions can, in some cases, increase durability risks. Indeed, diamonds do occasionally chip or break, but it’s pretty unusual for that to happen during normal wear.

The most common way for a diamond to get damaged is during the setting process, while the jeweler puts pressure on the stone to securely set it.

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Inclusions Vs. Blemishes

Inclusions are defined as characteristics internal to the diamond, but they may also extend to its surface. 

On the other hand, blemishes are confined to the diamond’s surface and are commonly minor in nature. 

While inclusions are plotted in red, blemishes are plotted in green on a grading report.

Some examples of blemishes include chips, nicks, scratches, bruises, naturals, and polishing marks. Unless unusually large in number or size, blemishes will rarely affect the performance and beauty of a diamond.

What Are Feathers?

Feathers are small fractures within the diamond that give a white featherlike appearance. 

While common and relatively easily disguised in brilliant-cut diamonds, feathers that run closer to the diamond’s surface could potentially cause some durability issues.

What Is A Natural?

A “natural” is the surface feature caused by the diamond cutter leaving a small part of the rough diamond crystal on the finished stone. Why would they do that? 

To avoid having to remove additional material all around the perimeter to maintain symmetry.

For instance, it’s done to retain the carat weight that would otherwise be lost by removing the natural completely. 

Usually, naturals are small and confined to the girdle area. However, they could be quite large if the diamond cutter was taking liberties.

A natural is typically considered a blemish – but if it’s notably indented, it falls into the inclusion category and is called indented natural.

Interesting Crystal Inclusions

There are a lot of other crystals and minerals that can be trapped within a diamond during the formation process. These include rubies, sapphires, and garnets – just to name a few. 

Sometimes they can be quite beautiful to see under magnification. 


An interesting type of inclusion that can be pretty remarkable is known as a reflector. This type of inclusion just happens to be located in an area within the diamond that gets mirrored around the stone, making it look like multiple inclusions.

Concrete Vs. Transparent Inclusions

Some inclusions, such as crystals, can be rather concrete in nature. They have a defined shape and are generally opaque. 

Other inclusions such as clouds, graining, and twining wisps are amorphous – and are generally very transparent. Some people prefer these transparent types of inclusions to more concrete and easier-to-notice types.

Less Common Diamond Inclusions

There are many inclusions that are less frequently seen – especially in high-quality diamonds – such as knots, etched channels, cavities, and laser drill holes.

Just as the name implies, cavities are holes – or divots – at the diamond’s surface that appear to have been scooped out. Cavities are usually associated with knots which are defined as crystals that come to the surface.

In some cases, these crystals can be dislodged, leaving a cavity behind. You can think of a knot in a piece of lumber and how it can be punched out; it’s similar to that. 

But with diamonds, it’s not that easy to dislodge a knot. 

It’s unlikely that a knot would come out and leave a cavity during normal wear – this can happen during the cutting process.

An etched channel is defined as a linear cavity that is a result of chemical processes during formation. Like cavities, if they’re tiny enough, they don’t pose a significant issue. 

However, etched channels can sometimes increase durability risk, depending on their location and size.

These channels can also trap dirt, which can make them more visible over time. While etched channels can be difficult to clean at home, professional cleaning will remove any buildup.

As for laser drilling, it’s a treatment that causes a small threadlike tunnel within a diamond. 

A laser beam is precisely aimed at a dark inclusion, after which a hole is drilled – and a strong acid is then introduced under pressure to dissolve the inclusion.

This treatment doesn’t improve the diamond’s clarity grade but can make some inclusions much less visible.

Diamond Grading Reports

A report from a diamond grading lab such as GIA and AGSL will provide a plethora of information that’ll verify the stone is natural and provide qualitative analysis to communicate the looks and performance of the diamond.

However, these grading reports have limitations. 

Seeing the stone, belong able to see advanced diagnostic images of it, and getting consultation from a diamond expert are also significant additions to the information contained on a lab report.

In addition to dimensions, carat weight, cut quality, clarity, and color grades, the Stone Plot and Keys to Symbols map the characteristics that positively identify the gem and support the clarity grade. 

It’s crucial to know which characteristics are necessarily mapped. 

Inclusions are listed in order of their effect on the clarity grade under the Stone Plot. The first characteristic listed is the grade setting inclusion – features listed last are the least impactful.

The Comments section of a diamond’s grading report is also noteworthy. There, you can find essential factors of the diamond that might not be covered elsewhere in the grading report. 

For example, a detail of the inscription can be found there if the stone is inscribed.

Also, clarity features relevant to the stone’s appearance might be noted in the comments section. For example, it will cover characteristics not included in the Stone Plot.

It’s often necessary to understand the Stone Plot and the comments section to understand the appearance of the diamond and any potential issues better, too.

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Eye-Clean Diamonds

When talking about inclusions in diamonds, one of the most common baselines for consumers is the concept of “eye-clean.” That means different things to different people. 

Essentially, an “eye-clean diamond” refers to a stone with no inclusions visible to the naked eye. The general consensus is that a diamond can have inclusions – but an inclusion that’s visible to the naked eye is a deal-breaker for many people.

However, there is quite a bit of subjectivity on this matter. For example, it might be technically possible to spot an inclusion with some effort and only from a certain angle.

Would that be a deal-breaker to you? Do you want to ensure that the first thing you see when you look at your diamond isn’t an obvious inclusion jumping out? 

The thing is, people will differ in their tolerance levels. 

So, consumers should have a solid understanding of what’s important to them. On top of that, people should ensure proper communication between them and their jewelers to dodge any disappointments.

Transparency Issues

One of the more subtle – yet essential – adverse effects of diamond inclusions takes the form of reduced transparency. 

We tend to think of diamonds as perfectly transparent gemstones – but some diamonds have a slight fogginess to them which often goes unnoticed. 

Only by comparing with an utterly transparent diamond can the issue of fogginess be confirmed. With that said, a diamond with a transparency issue will never have peak performance in terms of sparkle – even if perfectly cut and eye-clean. 

Therefore, it’s key to understand what clues to look for when spotting any potential transparency problems.

What Are The Worst Diamond Inclusions?

As we already mentioned, inclusions within diamonds aren’t inherently “wrong” – almost all diamonds have some inclusions. 

It’s mostly a matter of the extent of that inclusion. 

Theoretically speaking, surface-breaking inclusions such as knots, cavities, and feathers can, in some cases, lead to concerns regarding durability. However, if the inclusions are small enough, such durability concerns are typically not warranted.

Diamonds with a VS1 clarity grade and above are almost always unaffected by durability and transparency issues. In most cases, SI1 to VS2 graded diamonds are also free of durability concerns.

Diamonds with S12 and below clarity grades are the ones that need to be carefully evaluated due to potential durability and transparency issues.

Learn More: Can You Remove Inclusions From a Diamond?


So, what are inclusions in diamonds?

Inclusions, as the name implies, are imperfections that are “included” in a diamond. Naturally-formed inclusions are a testament to the oh-so-extreme conditions required for these gorgeous gemstones to be created deep below the Earth’s surface. 

They present small parts of the stone’s journey, eternally captured within dazzling facets of the diamond.

If you’re looking to purchase a diamond, be sure to assess the positioning of any inclusions; it’ll have the most significant impact on the overall appearance and beauty of the diamond. 

Apart from reviewing the grading report, be sure to talk to a professional jeweler about other concerns you might have.

Once you’ve chosen your gem, any inclusions plotted on the map serve as unique birthmarks, identifying the stone as yours. And there will never be another diamond like it!

Related Read: Anatomy Of A Diamond