15 Types of Diamond Inclusions Explained (What Are They?)

What Are Diamond Inclusions?

Inclusions happen because diamonds are subjected to lots of pressure and high temperatures deep into the mantle of the earth. Under these conditions, various clarity characteristics are present in and on diamond crystals.

There are very few crystals that don't have external or internal inclusions. These are sold as the flawless diamond clarity grade, also know as an F on the clarity scale. 

Lab made diamonds also have inclusions, but instead of being made of mineral crystal, they have metallic inclusions. This is often how jewelers can tell a lab grown diamond from a natural mined diamond.

Are Diamond Inclusions Good or Bad?

I'd say it's unfair to label diamond inclusions as good or bad. After all, inclusions are the fingerprint of your diamond. There will never be another diamond with those same characteristics in the world. 

Plus, it'd be more accurate to put inclusions into desirable and undesirable categories. The most desirable would be a flawless or internally flawless diamond, but let's be honest, there's no reason to spend that kind of cash. 

If you want an eye-clean diamond, you should check out our tips & tricks to figure out the cheapest route to getting your perfect diamond, without paying the cost for perfection. 

To fully understand diamond inclusions and how they affect your diamond appearance in different ways, it's important to first understand the anatomy of a diamond. 

The diamond body is split up into two halves. The top half is referred to as the crown. The crown contains the table of diamond, which is the face up view when looking down on it as if it were set in an engagement ring. The crown also contains the girdle, which is the outermost edge of the diamond going around its shape. The crown also contains many crown facets, which are generally cut into brilliant facets. 

The bottom half of the diamond is called the pavilion. The pavilion is the cone shaped part of the diamond, at least in a round cut diamond. The pavilion also has its own long facets as well as the very point at the bottom, referred to as the culet. Note that not all diamond shapes have a culet or shorter facets. 

Whether diamond inclusions should be become an issue to your diamond depends greatly on the type of diamond inclusion, and the location. Many inclusions aren't noticeable on the girdle of a diamond, but are more apparent in the pavilion. This is why it's good to make sure you're familiar with the parts of a diamond.

What Are The Different Types of Natural Diamond Inclusions?

Before you start assigning diamond inclusions as bad, keep in mind that there are many different types of inclusions. Not only that, but each type of inclusion ranges in size and location, so one type of an inclusion may look worse on one center diamond, but fine on a different one. 

Nearly all diamonds have natural inclusions. Thankfully, most of them can only be seen under 10x magnification. Here are some of the different types of natural inclusions you can find within a diamond.

Crystal Inclusion

A crystal inclusion is basically exactly how it sounds. A mineral crystal gets trapped as the diamond is forming. It is the most common inclusion type. The can be colored or colorless, depending on the mineral trapped inside.

Colored inclusions can be reddish from garnet crystals, greenish from peridot, but most often black from bits of carbon. You won't usually see diamonds with red or green inclusions because these lower graded diamonds are not seen as sellable. 

Crystal inclusions are very prevalent in diamond clarity grades below VS2. Most I1 diamonds have many crystal inclusions. Most crystal inclusions are too small to, so your main concern would be your diamond's appearance rather than durability. Avoid the big black mineral inclusions. 

Feather Inclusion

Feathers are usually everyone's favorite type of diamond inclusion. Small feathers can be viewed as unique diamond characteristics displayed within the diamond's appearance. For feather inclusions to happen to a diamond, there has to be a break within the gemstone. A can small crack or fracture can cause this to happen. 

While feathers are unique and neatly resemble little white bird feathers, be aware of the location of these types of inclusions. Feather inclusions near the diamond's girdle or feathers located near other cavity inclusion types can leave the diamond weakened in durability. If struck in that area, your diamond would be more susceptible to chipping. 

Feather inclusions can be seen with the naked eye and under 10X magnification, depending on the diamond's clarity in combination to its other diamond grades. When feather inclusions are plotted on a GIA or AGS grading report, you'll see them marked as a diagonal squiggle running from right to left.

Pinpoint Inclusion

Pinpoints are another common type of inclusion. These can be seen as tiny black or white dots within the diamond, but mostly white. These are very small pieces of crystals or minerals that have been trapped in the diamond. 

Pinpoint inclusions can be found in diamonds with higher clarity grades, like VS diamonds. They are usually noticeable under 20X magnification, but can't be seen with the naked eye.

Very Slightly included diamonds most often contain white pinpoints. Because pinpoints can be very difficult to locate, you won't always see them plotted on a grading report. They may indicate that there are pinpoints, but with undisclosed locations. 

Pinpoint inclusions are not harmful to your diamond, nor do they really impede your diamond's brilliance and shine. However, if there are three or more pinpoint inclusions, they can create another type of inclusion altogether. 

Cloud Inclusion

If there are three or more pinpoint inclusions within the same area on the diamond, it creates the diamond inclusion known as a cloud. Cloud inclusions are white colored and have a hazy like appearance. In fact, cloud inclusions don't really resemble the big white fluffy clouds we see in the sky. I'd say they tend to look like what happens when wisps of smoke just sit in the air. 

Cloud inclusions can be be big or small, depending on the number of pinpoint inclusions within the cluster. These types of inclusions don't affect diamond durability and they can usually be seen in SI1 or SI2 diamonds and below. Most VS1 diamonds won't have noticeable clouds to the naked eye.

 However, if there are more pinpoints within the cluster, the cloud will appear more prominent. The least visually affecting location of a cloud is deeper into the stone instead of the surface of a diamond. On a grading report, you can found cloud inclusions indicated by a dotted circle on the diamond plot.

Internal Graining

When a diamond has internal graining, it will have faint white white lines going in the same direction. It resembles a group of perfect lines as if they had been scraped cleanly on the side. This inclusion is caused when the diamond grows irregularly beneath the surface of the earth. 

Most internal graining will only appear as faint, smooth lines. But in diamonds where the graining is more severe, it can cause the diamond's appearance to be more reflective in the area and also look like creases. In really bad quality diamonds, they can have color to them.

If the graining looks more like threads or a cluster going in different directions, it's called a grain center. Thankfully, internal graining doesn't seem to affect overall appearance because they're more common in the pavilion, or the bottom half of a diamond. But if you find yourself unfortunate enough to have graining in the top or table of your diamond ring, it could be visible. 

When a graining type inclusion is shown on a grading report, the diamond plot will have a dashed squiggly line running from the bottom left across to top right. Most of the time however, graining is talked mentioned in the comments section rather than on the diamond plot. 

Needle Inclusion

If you know anything about colored gemstones, you probably have seen needle inclusions. They are long thin inclusions that are usually white in diamonds. These inclusions are actually desirable by some gemstone collectors. Below is a snippet of a video that explains more in detail.

But while these excessive needle inclusions are seen as beautiful in quartz, it's quite the opposite when buying diamonds. A diamond with that many needles would never be sold on the market. However, diamonds with small needles can be. 

These types of inclusions don't really impact the diamond to the unaided eye, generally because they are so thin and small. They can be seen under 10x magnification, but don't cause issues to the face up view of the diamond unless they appear in clusters. This is less likely to happen in eye clean diamonds like VVS diamond clarity (VVS1 or VVS2). 

Needles on a grading report will be indicated as a forward slash when plotted.

Twinning Wisps Inclusion

A twinning wisp happens when other inclusions evolve, so to speak. A group of clouds, pinpoints or crystals can create twinning wisps. This type of inclusion is created when natural diamonds are forming.

When the conditions that cause a diamond to form become undesirable, the diamond may stop growing. If those conditions become favorable again, the diamond can start growing again. 

When it reboots its growth, the crystal inclusions grow in different directions, creating little wisps as they grow. Fancy shape diamonds (diamond shapes other than round) are created from twinned crystals, so these inclusions are common within the lower clarity grade tiers.

Indented Natural

An indented natural inclusion is pretty much just as it sounds. It's a natural indent in the diamond. Usually, this is a small area near the girdle that remains unpolished by the jeweler. 

Most of the time the diamond cutter discovers they can't cut the indented natural out without costing the diamond too much of its diamond carat weight.

Thankfully, Indented naturals aren't an inclusion type to be concerned about. If anything, it serves as a reminder of what your beautiful diamond once was before it was polished. And as long as your indented natural inclusion isn't more pronounced or large, it really shouldn't cause any issue. 

Indented natural inclusions are marked as the following symbol on a grading report: 

What Are Diamond Inclusions To Avoid?

Knot Inclusion

A knot is a type of crystal inclusion that reaches the surface of the stone on a polished diamond. When looking a knot under magnification, you'll notice how it looks like a hump on a diamond facet. 

Knots aren't found in eye clean diamonds, so expect to see more of them in SI1, SI2, and I diamonds. These visible inclusions can be seen with or without magnification, you won't see them in higher grades on the diamond clarity scale. 

You should be careful when buying diamonds with surface blemishes like knots. While they may not impact your diamond immediately, they can affect its durability in the long run. Inclusions close to the surface make your diamond vulnerable to chipping and cracking. 

On a grading report, a knot is represented as a a green oval outline facing from east to west with a smaller red oval fit inside of it.

Chip Inclusion

A diamond with a chip in it is also considered an inclusion.  A chip is a little opening within the diamond. Most chips happen near the girdle or on the culet, or bottom point of the diamond in some diamond shapes. 

Chipped diamonds usually happen after a customer receives a diamond, usually from banging it on something pretty hard. This could be a countertop, edge of a wall, doorframe, etc. There are a couple things you can do to help reduce the chances of your diamond chipping. You should avoid engagement ring diamond shapes with pointy ends, like a marquise or pear cut diamond. 

Some diamonds have small chips on them and will be marked as this symbol ^ on a grading report. Small chips aren't usually a problem, and diamonds can be recut to get rid of those. Some diamonds that have larger chips loose some of their carat weight.

Read Also >> What does diamond cut actually mean?

Cavity Inclusion

Similar to cavities in the mouth, diamonds can have cavity inclusions as well. This is an opening on the surface of the diamond. In diamonds, cavities are usually very small and unnoticeable unless under magnification. 

Cavities happen when a diamond has an internal inclusion that has fallen out, like a mineral crystal. The cavity is the tiny hole that crystal left behind. You'll be less likely to notice diamond cavities that are in the crown or near the girdle. Cavities in the pavilion, or the bottom part of the diamond are more noticeable. 

Cavities aren't necessarily harmful to your diamond or for your engagement ring, but they can present some clarity issues and be more difficult to clean. The little cavities trap in dirt and oils in the cavity, turning it black. Trying to get between there to clean with a soft brush would be a pain. Just keep that in mind if you're considering buying diamonds with cavity inclusions in them. 

On a grading report, a cavity inclusion is annotated on a diamond plot as a green oval going from east to west with diagonal red lines inside of it. 

Etch Channel

There's a bit of debate if an etch channel is manmade or a natural diamond characteristic. But gemologists and scientists say that an etch channel is a natural occurrence in a diamond during its growth. 

The etch channel can be confused with the laser drill hole, but they do a couple things that drill holes don't. They are similar in the ways they look like a deep tunnel, but etch channels can also appear in parallel lines. Etch channels are the result of the diamond's experiences under conditions in the ground. The intense pressure and heat can scar the diamond, leaving etch channel inclusions. 

Etch channels don't affect the overall durability of the diamond, but like cavities and drill holes, these types of inclusions are known for trapping oils and dirt, turning them black. This can affect overall diamond clarity, especially if these inclusion are located in the pavilion of a diamond. 

On a grading report, an etch channel will be a red rectangle with a green rectangle of slightly smaller size fitted inside of it. 

What Are The Different Types of Man-made Inclusions?

When we refer to an inclusion, we're usually talking about characteristics that have happened to the diamond as it was forming. However, there are inclusions that are the result of intentional and even unintentional actions by jewelers to enhance clarity or as accidents when cutting a rough diamond.

Bearding

Bearding happens to a diamond's girdle, or the edge of the top of the diamond all the way around. On diamond grading reports, gemologists will grade the girdle as Slightly Thick to Very Thick, Medium, Thin to Very Thin, etc. 

Bearding cause the girdle of a diamond to appear whitish and fuzzy. Bearding is not a natural inclusion, but usually happens because of poor polishing or cutting on the jeweler's behalf. However, it can happen over time to the diamond, but this isn't a very common thing. 

The fuzzy edge of the diamond is actually a ton of tiny little feather inclusions. So, is a bearded diamond okay, or a dealbreaker? Depends on the girdle thickness itself. Bearding doesn't usually cause visual issues, but it can if the girdle is already Very Thick. The bearding would cover more of the diamond and may cause it to look unappealing. 

But this isn't too common. Most bearding can only be seen under a jeweler's loupe or gemscope. Bearding isn't noted on a diamond plot, but would be mentioned in the comment section of a grading report. 

Bruise

Normally, when we think of bruising, we think of soft surfaces, like skin or a mushy fruit. Since diamonds can be fragile when hit hard enough, they too, bruise. A sharp blow to the diamond causes a small series of feather inclusions to appear. 

You might be surprised to know that a bruise is most often caused by a diamond cutter whose not paying to closely to his work. This "inclusion" can happen when jewelers cut diamonds using machinery like a polishing wheel. If pressed against this tool too hard, a bruise will appear on the diamond. 

If your diamond has a bruise, it'll most likely be found in the crown facets of the diamond. This is the angled top half of the diamond with all of the face-up facets. When plotted on a report for clarity grading, a bruise will be displayed as a small x.

Internal Laser Drilling

If your diamond has a laser drill hole, it means that the diamond has been subjected to clarity enhancements via a laser drill. But these holes are probably not near as big as you're picturing them if you're unfamiliar with this diamond procedure. 

The holes that are created by the lasers are very thin, almost hairlike. These holes make a way to an internal inclusions in order to dissolve the inclusion using acid or melting hot heat near it. Laser drilling is not a common procedure in diamonds and is actually required to be told to a customer if the procedure has been done to that diamond. 

Previously, the Federal Trade Commission didn't require laser drill hole procedures to be divulged because the enhancement doesn't make the diamond look any worse. The diamond community has always divulged these procedures, but now the FTC backs them up as well. 

You're more likely to find internal laser drilling in an SI1 diamond or an SI2 diamonds. These are diamonds that generally have few visible inclusions. Without this procedure, it's possible your diamond might've been graded an I1 by a skilled grader. VS1 and VS2 diamonds are more likely to be eye-clean on their own, so these enhancements aren't needed in higher clarity grades. 

Metallic Inclusions

Metallic inclusions only happen in synthetic diamonds, aka lab diamonds. Lab diamonds are real diamonds put into chambers that emulate the conditions underground. Scientists can create real diamonds in a lab in weeks instead of the billions of years it takes for diamonds to form in the ground. 

Metallic inclusions are natural in a lab created diamonds, but not found in a natural diamond. They also can only be seen under magnification and they don't cause your diamond any harm. You won't find I clarity lab diamonds for this reason. All lab diamonds should be eye clean. 

Should You Buy A Diamond with Inclusions?

Just because a diamond has an inclusion or a even a few, doesn't mean it's not worthy of your purchase. While some inclusions are unsightly and dark, there are plenty of minor inclusions that won't impede appearance or compromise the integrity of the stone. 

The great thing about buying diamonds online is that they're already 40% cheaper than what you might find in the store. So, you could buy a more eye-clean clarity grade for less than you'd pay in store. 

Most inclusions are no big deal and settle on personal preference. However, you should always purchase from a retailer that allows you to see the diamond, be it online in a 360 viewer, or in  salesperson's microscope. This will help you avoid the more serious inclusions that could impact your diamond negatively. 

So should you buy a diamond with inclusions? If you can afford it, I'd say skip the inclusion and go to an eye clean clarity grade like VS1 diamonds. But if you're unable, there's absolutely nothing wrong with buying a diamond with inclusions. The choice is yours.