Appraising a Diamond with a loupe

Every thing You Want To Know About Diamond Readability

Diamond clarity is one of the 4Cs of diamond classification. It is a measure of the extent to which a diamond contains internal (inclusions) or surface (blemishes) flaws. Each inclusion or blemish will detract from the brilliance and clarity of a polished diamond. The flaw will interfere with the refraction of light as it travels through the diamond.

Diamond Clarity Chart

Here are two simple diamond clarity charts to help you understand how diamond clarity works.

The first chart shows the diamonds in their order (ranging from SI2 – F Clarity) as they are without circling the issues. The second chart shows the visible dominant inclusions on the diamond that would be plotted on a certificate.

Diamond Clarity Chart

Here is the second chart. We’ve circled the visible inclusions. Please note that the IF Clarity and F Clarity don’t have any visible inclusions.

Diamond Clarity Chart Infographic With Red circled Inclusions

What Causes Inclusions and Blemishes in Diamonds?

Diamond Inclusions in Brilliant Cut DiamondAn example of a diamond with lots of inclusions

According to modern-day estimates, diamonds will take over an exhaustive period of time to form. Despite their unique structure and composition, it is inevitable that the stones acquire flaws and imperfections along the way. These imperfections are called “inclusions”.

The diamond cutter will take great effort to work around these flaws. A long process, usually complicated by fault lines, dictates where the cut will be made.

Flawless diamonds become extremely rare once diamond sizes get above 2 carats. Most rough stones large enough from which to produce larger diamonds rarely are free of inclusions.

How to Find Inclusions?

Loupe with chain

Diamonds are graded using a 10x Loupe, a special magnifying lens used by jewelers and other industries to get a close-up view of things that might not be seen with the naked eye.

Blemishes, being surface issues, are usually easier to see than inclusions, and occasionally may be located using the naked eye. Inclusions, on the other hand, can’t. If a very large inclusion can be seen without a loupe, the diamond is of poor quality. Poor quality diamonds will usually be used for industrial cutting types of equipment.

One exception is with black diamonds. Black diamonds aren’t actually black. They are so included that light cannot escape, giving the appearance of the diamond being black. Black diamonds, whilst rare, are not generally sought after. They aren’t usually used unless explicitly specified for a certain design of a ring or jewelry piece.

If inclusions or blemishes cannot be avoided in the finished stone, the stone will have been polished in a special way. Usually, the cutter will try and position the inclusion as close to the girdle as possible. Inclusions beside the girdle are harder to see and have less effect on the brilliance of the diamond.

Types of Inclusions and Blemishes

Examining an engagement ring with a loupe

Diamond flaws can occur in several different forms. Some are internal, which class as inclusions and others are surface faults – often man-made – and are known as blemishes.

Fully understanding inclusions is beyond the scope of this article, but in this section, we will try to familiarize you with the basic inclusions and how to identify them.

Crystal Inclusion

Crystal Inclusion inside of Included Diamond

Plotting Symbol on Certificate Report Plot: Red circle.

The crystal inclusion is without a doubt the most famous type of inclusion, and usually the most easily noticeable as well.

A crystal is a mineral crystal that is contained inside the diamond. The larger the crystal (and the more central-placed it is), the lower the grading.

The color of the crystal will also play a factor in the GIA certification. White crystals are considered less desirable than black crystals (some say because the white crystals can also play around with the less light coming in and out).

Pinpoint Inclusion

Pinpoint Inclusion in Round Diamond

Plotting Symbol on Certificate Report Plot: Red dot.

Pinpoint is when a minute crystal has become trapped within the diamond as it forms. In order to qualify to be a pinpoint inclusion, it has to be non-visible to the naked eye (without the assistance of a loupe).

Even when examined with a 10x loupe, a pinpoint inclusion should look no larger than a tiny dot. They are complete Needles are similar to pinpoints but are thought to have been stretched as the diamond crystal grows in size. In isolation, pinpoint and needles don’t usually detract from the overall appearance of the diamond.

Needle Inclusion

Needle Inclusion inside of a brilliant diamond

Plotting Symbol on Certificate Report Plot: Red line.

A needle inclusion is a thin and long crystal inclusion that extends in a vertical or horizontal direction. Just like a pinpoint, a needle inclusion has to be non-visible to the naked eye (without the assistance of a loupe).

If the needle inclusion is visible to the naked eye, it is considered a crystal inclusion and not a needle inclusion.

Under a 10x loupe, the needle inclusion looks like a small stick, usually quick straight but sometimes a little curved as well.

Cloud Inclusion

Cloud Inclusion in a Round Diamond

Plotting Symbol on Certificate Report Plot: Red dotted circle.

A cloud inclusion is a tightly grouped collection of pinpoint or tiny needle inclusions that together create a hazy-like cloud within the diamond. If sufficient in number within a small location, a cloud can actually cause the loss of sparkle in the diamond. Cloud inclusions are amongst the most common of all inclusion types.

Tiny clouds on the side of the diamond can still qualify it to stay within the VS Clarity range, but if the cloud is bigger or closer to the center, the diamond will usually be within the SI Clarity range or lower.

Twinning Wisp Inclusion

Twinning Wisp on Inclusion Diamond

Plotting Symbol on Certificate Report Plot: Red curved line with short perpendicular lines just before each end.

Wisps are is caused by pauses in the crystal growth. Occasionally, a diamond crystal will stop growing due to changes in external conditions. Eventually, things will change again, and the diamond will continue growing. This causes streaking or cloudiness around the stop/start point and is actually a collection of various types of inclusions (pinpoints, feathers, crystals, and needles combined).

A twinning wisp inclusion will almost always mean that the diamond has at least an SI Clarity or lower.

Knot Inclusion

Knot Inclusion inside of a round cut diamond

Plotting Symbol on Certificate Report Plot: Red circle surrounded by a green circle.

The knot is one of the worst inclusion to have on a diamond. It is a rogue crystal that extends partially (or fully) until a surface. Aside from the fact that a knot inclusion is almost always easily eye-visible, it also presents a critical weakness to the strength of the diamond. Similar to a pinpoint flaw, knots are when the rogue crystal is at the surface of the polished diamond, and cannot be eliminated.

Feather Inclusion

Feather Inclusion in a Diamond

Plotting Symbol on Certificate Report Plot: Red squiggly line.

A feather is a crack within the diamond crystal. The shape of this inclusion literally looks like a father, hence its name. Depending on the location, they can seriously affect the durability of the stone and are a weak spot within the diamond. Feather inclusions are commonly responsible for chips in polished diamonds. They usually resemble a feather, hence their name.

If the feather breaks to the surface, the feather-like inclusion will now be called a cavity.

Small (non-serious) feathers can still qualify as a VS Clarity diamond, but large feathers will almost always automatically make a diamond clarity qualify as SI Clarity or lower.

Surface Graining

Graining Inclusion in Round Diamond

Plotting Symbol on Certificate Report Plot: Green Broken Lines.

Ideally, diamond crystals will grow at a fairly constant rate. This gives us the best clarity in rough stones. Graining occurs when the growth rate is irregular. Extra stresses in the crystal are caused by sudden spurts or slowing of the growing process. It manifests itself in streaking within the diamond.

Because graining is caused by crystal irregularities, the manifestation in the diamond varies greatly from stone to stone.

Indented Natural

Plotting Symbol on Certificate Report Plot: Green angle marker under a red angle marker.

Occasionally, a diamond crystal will contain natural indents. Most can be removed with careful cutting and polishing, but some remain. They are usually around the girdle, thereby limiting the detrimental effect on the cut diamond. This inclusion will follow the original pattern of the raw diamond.


Polish Marks

The vast majority of diamond surface blemishes are the result of poor polishing. These are commonly caused by inconsistent pressure when polishing, or using too much heat. The result is a dulled appearance on one or more facets.

Bearded Girdle

Bearding occurs around the girdle of a diamond if the bruting, or cutting, part of the process is not of sufficient quality. It produces hair-like wisps on the edges of the girdle, hence the name.

Lizard Skin

Another result of insufficient polishing skills, lizard skin is a rippled effect on the surface of the polished diamond. This blemish appears like lizard skin, hence the name.


Abrasion is minute nicks along facet edges. It gives the edges a dull, often fuzzy appearance.

Why Some Inclusions Are Better Than Others

13025 Customer using a Loupe on a Diamond and Sapphire Halo Engagement Ring in Showroom

Ideally, all diamonds would be flawless, but that is not the case. Far from it, in fact. Almost all diamonds have some flaw or other, whether an inclusion or surface blemish. As polishing techniques have improved, we now see fewer blemishes as a result of the manufacturing process. Some natural surface flaws do occur, but skilled polishers can usually avoid them. Internal flaws, though occur in almost all diamonds.

If you had to choose a diamond flaw to have, pinpoint is about the “best”. Single pinpoints don’t generally affect the clarity of the diamond significantly. They are certainly not visible without 10x magnification. As a result, diamonds with only one or two pinpoint inclusions and no others are very expensive and rare.

Cloud inclusions are actually very common. because of this, a lot of diamonds have cloud flaws. Most are fairly minor issues, however, and will not be obvious. The rest will depend entirely on location and size. During the grading process, diamonds are viewed from the crown down. If flaws are not visible from this angle, they will often not affect the grade too much.

Diamond Clarity Grades

The clarity of a diamond can make a big difference in its value. The higher the grade, in short, the rarer the diamond. This is especially true with diamonds over 2ct in size. To differentiate between the various levels of clarity, we use a scale from the Gemological Institute of America (GIA). They range from Flawless to Included, with six main grades. Some grades have different levels, meaning we have eleven grades in all.

Flawless (FL)

As the name suggests, a flawless diamond has no internal or surface flaws under 10x magnification. Such diamonds are so rare that few dealers have them available to buy. Many only appear for sale at specialist auction houses.

Here are some examples of engagement rings that contain flawless diamonds in the center.

Internally Flawless (IF)

With IF diamonds, only surface blemishes are present. These are only visible, again, under 10x magnification. IF will usually be the best grade available through general retailers but, even then, they are not commonly seen.

Very Very Slightly Included (VVS)

VVS has two sub-grades – VVS1 and VVS2. Inclusions in VVS diamonds are difficult for even a skilled grader to see under magnification. Although still quite rare, VVS diamonds are much more easily available than IF diamonds.

Here are some examples of rings with VVS1 and VVS2 diamonds in the center.

Very Slightly Included (VS)

VS1 Diamond with markings

Inclusions in VS diamonds are usually easy to spot for a skilled grader under magnification. The grade is broken down into VS1 Clarity and VS2 clarity. It is the VS grade that makes up the majority of diamonds bought today.

Determining between diamonds of vs1 vs vs2 is very complicated and can only really be done by an expert gemologist.

Shop some rings that have VS1 clarity and VS2 clarity diamonds inside.

Slightly Included (SI)

By the time we get to SI diamonds, flaws are easy to spot under magnification. Occasionally, some SI2 diamonds may also have inclusions visible to the naked eye. Many dealers will not stock SI diamonds, especially SI2, as they are usually quite low value unless exceptionally large.

Browse our selection of SI1 and SI2 diamond rings.

Click here to learn about “SI3 Clarity”.

Included (I)

Inclusions in any of the 3 I grade diamonds are obvious under magnification. They are also often easily visible without. Many I3 diamonds end up in cheap jewelry or even in industrial applications, rather than in engagement rings. Brilliance is greatly affected and demand is generally low for I graded diamonds.

Due to the quality that we require in our collection, we don’t have any diamond rings that are I1, I2, or I3 clarity. We always caution our customers that I1, I2, and I3 are diamond inclusions to avoid.

Any diamond that is too flawed will be very undesirable to sell later if you ever choose.

Which Clarity To Choose

Customer With Engagement Ring on Layaway Program from Estate Diamond Jewelry

Budget will be a big factor when purchasing any diamond. If money is less of a consideration for you, then by all means go for the best you can get, with VVS clarity an excellent choice. If, though, your bank account is not bottomless, then VS clarity diamonds are a terrific compromise of grade and price. VS diamonds do have flaws, but they are rarely visible with the naked eye. As nobody you show your engagement ring to will be carrying a jeweler’s magnification loupe, unless they are a jeweler, the diamond will appear all but perfect.

Perhaps surprisingly, a VS2 diamond may be as little as a quarter of the price of an IF or even VVS1 diamond. This makes them a very attractive option. Available numbers of VS diamonds are also much higher than VVS or IF stones. This increases your choice of size and cut.

How to Determine Diamond Clarity?

Appraising a Diamond with a loupePicture of Benjamin Khordipour examining the quality of a diamond

The clarity of a polished diamond is graded on a scale ranging from Flawless (FL) to Included Grade 3 (I3). Flawless diamonds have no visible inclusions or blemishes. Only around 0.02% of all the diamonds produced are flawless. Such grading plays a large part in the valuation of a diamond. Although Internally Flawless (IF) diamonds have no inclusions, they will have blemishes that can be seen at 10x magnification.

Diamond Clarity Example Red CirclesThe red circles show the diamond inclusions. This is considered a non eye-clean diamond

Slightly Included Grade 1 (SI1) is the 7th level of clarity on the scale and is considered the final grade at which inclusions cannot be seen with the naked eye. The next level (SI2) will have inclusions that are visible without magnification. They will also require a further, magnified, inspection to determine the extent of the effect of the inclusion on the overall clarity.

The Scale of Diamond Clarity

Diamond Clarity Chart for SI2

The full scale of clarity grading is as follows:

SI2 is usually visible but requires a closer inspection to determine the extent to which they affect the grade.

VS2 indicates inclusions may be detectable by the naked eye, under ideal viewing conditions.

SI1 and SI2 feature slight inclusions. SI1 Clarity is the lowest grade at which inclusions are invisible to the naked eye.

FL Flawless – No inclusions or blemishes detectable under 10x magnification.
IF Internally Flawless – No inclusions detectable under 10x magnification. Blemishes detectable under 10x magnification.
VVS1 and VVS2 Very Very Slightly Included – Inclusions are difficult to detect under 10x magnification, but are present. VVS1 inclusions are detectable from the pavilion, and VVS2 from the crown.
VS1 and VS2 Very Slightly Included – Inclusions clearly visible under 10x magnification, but usually classed as a minor.
I1, I2, and I3 Included – The lowest grade on the scale, and may have quite pronounced exclusions clearly visible to the naked eye.

Enhancing The Clarity Of A Diamond

We like to think of all diamonds as being truly natural. There are techniques however that can adjust the appearance of polished stones. One example is laser modification. Advanced lasers will drill a very fine hole from the surface to the inclusion. They then insert acid into the hole in order to bleach the inclusions and make it more difficult to detect.

The GIA won’t certify diamonds with fracture fillings. Fracture-filled diamonds aren’t true and are, therefore, unnatural.

Make sure that you check your certificate to determine that your diamond is truly natural.

Where Cut and Color Fit In

The cut and color of a diamond are probably more important than either clarity or carat weight. Even a flawless, colorless diamond will likely look terrible if the cut quality is poor. Similarly, almost all diamonds have color. Because of this, diamond size becomes a potential issue as similar color levels look different in large and small diamonds. Unless you are planning to use a yellow gold setting, try and get the faintest color diamond you can. Otherwise, setting in platinum or white gold can expose even the faintest hint of yellow in the diamond.

This is true regardless of clarity or weight. Again, though, use your eyes to guide you. Many non-colorless diamonds will actually look colorless unless side by side with a true D (colorless) color diamond. Let what you see in the diamond be the reason for your choice, rather than what it says on the grading certificate.

Which Clarity To Buy?

Old European Cut Diamond on paper

There is something very special about owning a flawless diamond. They are very rare and hard to come by. There is, however, a catch. They come with a significant price premium attached.

If you want an investment diamond, then IF and F clarity may be a good idea. If you don’t want to spend a lot of amount of money, you may need to settle for VVS1 and lower.

Although VVS2 and VVS1 are much more expensive than VS1 and VS2, most experts cannot even tell them apart.

If you want a diamond that shows no visible inclusions and is affordable our recommendation would be to focus on VS1 and VS2. If you don’t have a few small visible inclusions you can even drop to SI1. We strongly recommend not going less than SI1 unless you have no choice.

If you can live with the knowledge that your diamond is less than perfect, you can compromise without any perceived loss in quality. Unless an expert is examining your diamond, most average-quality diamonds will not show any inclusions.

Clarity vs Carat Weight

It’s a good question, and very difficult to answer. In practice, the smaller diamond, the less particular clarity you need to be. Conversely, the larger the diamond, the fewer flaws it needs to have. If you choose a large, low-clarity diamond, the lack of brilliance and sparkle can be noticeable.

It’s a vague answer, admittedly, but there is a pretty good way of applying the theory. With diamonds, although we talk about grades a lot, they are not the be-all and end-all. Instead of worrying too much about the clarity grade, look for diamonds that are eye-clean. By this, we mean diamonds in which inclusions cannot be seen without magnification. They may well be present, but if you can’t see them, why should it matter? This opens up options for you to look at larger diamonds than you might otherwise do.

We wouldn’t recommend going beyond VS2, especially at 2ct or above, but the choice is yours. With a little craft and guile, you can get so much more for your money that it will surprise you.

Antique Two-Stone Diamond Engagement Ring

Clarity is but one element which influences both the appearance and value of a diamond. With clarity, an expert eye is most important when assessing whether a particular diamond is right for you.

A reputable jeweler will always be willing to explain why a diamond has achieved a particular grade. Don’t be afraid to ask for help and advice.

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