Understanding Diamond Inclusions: A Guide by Stienhardt and Stones

Understanding Diamond Inclusions: A Guide by Stienhardt and Stones

During the diamond growth process, microscopic impurities or imperfections become present within the diamond. These imperfections are known as diamond inclusions. Inclusions are extremely common within diamonds and are essentially birthmarks that give every diamond uniqueness. You may have heard the phrase “no two diamonds are ever alike.” Well, inclusions are the reason. No two diamonds will have the same number, size, location and type of inclusions, even if they have the same clarity grade assigned by GIA or IGI.

During the diamond growth process, microscopic imperfections or impurities develop within the diamond. These imperfections are called diamond inclusions and are akin to unique birthmarks that impart individuality to each diamond. They ensure that no two diamonds are exactly alike in terms of number, size, location, and type of inclusions, even if they share the same clarity grade certified by renowned institutions like GIA or IGI.


Importance of Clarity in Diamonds

Clarity, ranked as the third most crucial characteristic in the 4Cs of diamond evaluation (after Cut and Color), refers to these tiny natural imperfections. Diamonds with fewer and smaller inclusions achieve higher clarity grades according to GIA standards. This grading system, recognized across the industry, ensures accuracy and consistency in diamond quality assessment.

Impact of Inclusions on Diamond Sparkle

Inclusions can affect a diamond's sparkle by obstructing the passage of light through the stone. Depending on their size, number, location, and type, inclusions may diminish light refraction and brilliance. Hence, the clarity scale serves as a benchmark to categorize diamonds based on their imperfections, ranging from flawless (FL) to included (I3).

The Diamond Clarity Scale

Diamond clarity grades span from FL (Flawless) to I3 (Included). Inclusions are examined under 10x magnification, where those in the higher clarity grades (FL, IF, VVS) are nearly imperceptible even to experts. As you move down the scale (VS, SI, I), inclusions become more visible, impacting both value and visual appeal.


Clarity Scale

Diamond clarity grades span from FL (Flawless) to I3 (Included). Inclusions are examined under 10x magnification, where those in the higher clarity grades (FL, IF, VVS) are nearly imperceptible even to experts. As you move down the scale (VS, SI, I), inclusions become more visible, impacting both value and visual appeal.

flawless diamond with no clarity inclusions

FL: Flawless

A FL diamond has no inclusions or characteristics (blemishes) inside or on its surface. It is extremely rare and is an exquisite symbol of perfection. Less than 0.1% of all gem quality diamonds are in this category. They have the highest premium and are typically found in smaller sized diamonds. With this clarity you cannot see any inclusions or blemishes even with 10x magnification and those too can only be found by a skilled grader.

internally flawless diamonds with no visible inclusions

IF: Internally Flawless

No internal flaws, only insignificant surface blemishes that do not affect brilliance.

diamond with a VVS1 clarity grade

VVS1: Very, Very Slightly Included 1

A VVS1 diamond has very minute inclusions that are extremely small, and often undetectable by many diamond professionals, even under 10x magnification. VVS1 offers a much better value than FL or IF and still has virtually the same appeal. Diamond sparkle is unaffected as the inclusions are so small that light is barely affected. The most common VVS1 inclusions are pinpoint and natural. Typically, VVS1 inclusions are only visible from the pavilion, under magnification. To the naked eye, the inclusions are not visible making these diamonds eye-clean. Learn more about VVS diamonds.

diamond with a VVS2 clarity grade

VVS2: Very, Very Slightly Included 2

A VVS2 diamond has very minute inclusions that are extremely small, but are slightly more visible under magnification than VVS1. This clarity grade is considered the best value of the higher clarities and does not compromise your diamond’s brilliance. Inclusions can rarely be found, even under 10x magnification. The most common VVS2 inclusions include cloud, pinpoint, feather and natural. Learn more about VVS diamonds.

VS1 clarity graded diamond with a very small inclusion

VS1: Very Slightly Included 1

A VS1 diamond has very minor inclusions that can be seen only under magnification. VS is a very popular clarity range. The inclusions in VS1 diamonds cannot be viewed by the naked eye and have minimal impact on diamond sparkle. The largest factor in grading a VS1 is the size of the grade setting inclusion. The most common VS1 inclusions include cloud, feather, needle, crystal, indented natural. Learn more about VS diamonds.

VS2 clarity graded diamond with very small inclusions

VS2: Very Slightly Included 2

A VS2 diamond has very minor inclusions that look only slightly larger than a VS1 under magnification. A VS2 is not noticeable to the unaided eye and is extremely popular because its value allows you to focus your budget on another Cut, Color or Carat. VS2 diamonds tend to have a few more inclusions than VS1 and the size is slightly larger, while still microscopic. The common VS2 inclusions include crystal, feather, indented natural, cloud and twinning wisp. The location of inclusions isn't very impactful in VS diamonds. Learn more about VS2 diamonds.

diamond with an SI1 clarity grade with small eye visible inclusions

SI1: Slightly Included 1

Additionally, we recommend choosing SI diamonds with more inclusions rather than a single inclusion. With a single grade setting inclusion, it must be larger and more visible in order to be an SI clarity diamond. The common SI1 diamond inclusions are crystal Slightly Included 1: a SI1 diamond will sparkle brilliantly even with its minor inclusions that may be invisible to the unaided eye. SI1 is extremely popular because its value allows you to focus your budget on another Cut, Color or Carat. It is considered a high clarity grade at a great price. In SI diamonds, it is recommended to choose diamonds with inclusions that are off center and closer to the girdle of the diamond. These are rarer to find and so they carry a Premium feather, twinning wisp, cloud, knot and indented natural. Learn more about SI diamonds.

Be wary of single crystals or clouds that they can be eye visible or make the diamond look hazy, cloudy or milky. Be sure to analyze diamonds on a case by case basis so that you are getting one of excellent quality.

diamond with an SI2 clarity grade with noticeable inclusions

SI2: Slightly Included 2

An SI2 diamond will possess high sparkle and is comprised by clarity inclusions that may be visible without magnification, when examined closely. Most SI2 inclusions are undetectable to the unaided eye. SI clarity grades tend to offer great value. Like SI1 diamonds, avoid larger, single inclusions. On the GIA report, these can be identified by the diamond plot where inclusions are marked or by the inclusion comments.

Avoid SI2 diamonds that have a grade setting inclusion that is cloud or a large, center crystal. Crystals in SI diamonds are typically black and so they are more visible without magnification. Common SI2 inclusions are larger crystals, twinning wisps, feathers, clouds and knots.

I1 clarity diamond with obvious inclusions visible

I1: Included 1

An I1 diamond will shine bright despite eye visible inclusions clarity inclusions. The inclusions can be visible without magnification when the diamond is closely examined, depending on size and location. I1 clarity grades can be very budget conscious, and can really allow you to reach a greater carat weight or desirable color grade. Diamonds in this category have little or no structural impact from inclusions, but it is recommended to avoid diamonds with a single, larger grade setting inclusion. Often, inclusions will reflect in other diamond facets, making them more noticeable.

Common I1 inclusions are large crystals, feathers, clouds, knots and activities. With Clarity does not carry any diamonds in the I2 or I3 range as the clarity inclusions in these really start to distract from the sparkle and the beauty of the diamond. I2 and I3 diamonds are not recommended for an engagement ring. However if you must choose an I diamond, stay within the I1 clarity range. For these diamonds, be sure to choose one in which the inclusions are scattered or spread on the diamond. If inclusions are very large or are concentrated in one area, this can really inhibit the sparkle of the diamond. Inclusions that are on the sides of the diamonds or closer to the edges can also potentially be covered by prongs. One more important consideration to make is that I clarity grade diamonds that have very clean looking plots but are still graded in the I range can be cloudy or hazy with a lack of sparkle. If selecting an I1 diamond be sure to consult with our gemologists to understand the look and value of the diamond before moving ahead with your purchase.

Pricing Effect

At Stienhardt and Stones, we specialize in both lab-grown and natural diamonds, each rigorously graded for clarity and quality by certified gemologists. Lab-grown diamonds, created under controlled conditions, offer a sustainable and ethically sound alternative to mined diamonds. They exhibit the same physical and chemical properties, including clarity characteristics, as natural diamonds.

Laboratory Grown Diamond Clarity vs Naturally Grown Diamond Clarity

Lab-grown diamonds are increasingly popular for engagement rings and jewelry due to their quality and environmental benefits. They undergo the same grading processes as natural diamonds, ensuring comparable clarity and brilliance. Stienhardt and Stones proudly offers both lab-grown and natural diamonds, each with its unique appeal and advantages.

Is Lab Diamond Clarity better than Natural Diamond Clarity?

When it comes to color and clarity, it's very difficult to tell the difference between laboratory grown diamonds and mined diamonds. Both lab made and natural diamonds possess the same razzle dazzle, physical, and chemical properties. The best and only way to tell the difference is by comparing their certificates.

At With Clarity, all of our diamonds come with an authentic report from an internationally-vetted lab. The International Gemological Institute (IGI) identifies all our lab stones and grades its cut, finish, proportions, clarity, and color. Whereas our natural diamonds come with an authentication report from the Gemological Institute of America (GIA).

Selecting a Clarity

Our key tips for selecting the right clarity grade:

  1. Clarity grade should always be selected in conjunction with the other 4 C's of diamonds. For example, we do not recommend select a D color, I1 clarity diamond. The most popular clarity grades are VS2 and SI1 because they offer the best value without disrupting diamond sparkle.
  2. Choose diamonds with inclusions that aren't in the absolute center of the diamond. More inclusions isn't typically a bad thing.
  3. Avoid diamonds with a single large grade setting inclusion because it is more likely to be visible. In diamonds under 0.75ct, inclusions are smaller and more difficult to identify. In diamonds larger than 0.75ct, consider an SI1 or higher clarity grade to avoid distracting eye visible inclusions. Additionally, if selecting a lower clarity grade, consider a higher cut grade as a well cut diamond can mask clarity setting inclusions to keep sparkle and brilliance high.
  4. Lastly, consider diamonds that have clarity inclusions that are not in the table or central facet of the diamond are more desirable. A better location for inclusions is under the bezel facets of near the girdle as they are harder to see or can be covered as well when being set in the ring.

Also consider shapes when selecting a clarity. Brilliant cut diamonds like round, princess, cushion, oval, pear, and marquise hide inclusions better than other cuts like asscher and emerald. When purchasing a step cut diamond, try to select one clarity grade one level better than that of a brilliant cut.

Diamond Clarity Popularity

Lab Diamond vs Natural Diamond Percentage in Inventory (due to demand).

Clarity Grade (lowest to highest) I1 SI2 SI1 VS2 VS1 VVS2 VVS1 IF
Natural Diamond Clarity 1% 4% 7% 30% 30% 26% 1% 1%
Lab Diamond Clarity 1% 5% 10% 30% 28% 21% 4% 1%

Values are estimated and can vary based on our inventory.

Expert Tips

  • Opt for Eye-Clean Diamonds: Choose diamonds with inclusions that are not visible to the naked eye, ensuring maximum brilliance and value.

    Consider Cut and Shape: Brilliant cuts like round, princess, cushion, etc., hide inclusions better than step cuts like emerald or asscher.

    Consult with Our Gemologists: Our team is here to assist you in selecting the perfect diamond, whether lab-grown or natural, ensuring clarity and value align with your preferences.

How is Clarity Graded

Gemologists always grade diamond clarity at 10x magnification. They identify and plot as many inclusions as possible. In diamonds below 1.00ct, there is typically a smaller GIA report called a dossier. A dossier has no diamond plot on the certificate. Diamonds larger than 1.00ct have a diamond plot on the GIA certificate.

Clarity grading is a subjective process. Trained gemologists identify the type, size, location and number of inclusions. They determine the grade based on a couple of inclusions and assign the grade. The diamond clarity rating or grade is an important factor to consider regardless of the size and shape of the diamond. Once a the inclusions on the diamond have been noted and mapped out. A diamond plot is used to record the location and size of these inclusions. The diamond plot is a sketch of the diamond face-up. It is shown on the GIA certificate or the dossier of the diamond. The different inclusions are shown with different symbols. Be sure to look at the diamond grade as well as the plot. GIA uses the color red to show internal inclusions and green for surface blemishes while black is used to convey extra facets. Oftentimes, the plot will not tell you about the severity of the inclusion so it is always important to also look at the clarity grade. Also be sure to look at the comments section on the GIA certificate to understand if there are certain inclusions that are not visible. Typically very small inclusions that are not visible under 10x magnification are noted in the comments section. For rule of thumb, a very busy looking plot with lots of inclusion markings means that the diamond is a bit less desirable.

Diamond Clarity Chart: I1, SI2, SI1,VS2,VS1,VVS1,VVS2,FL

Diamond Inclusion Types

Inclusions are natural, tiny imperfections that form either naturally or during the diamond cutting process. The majority of inclusions are naturally found within diamonds and are used to identify and distinguish diamonds. Here are the diamond inclusions you may find in a diamond or on a GIA grading report. All natural diamonds will have inclusions. It is immensely rare to find a diamond with no inclusions, and these diamonds carry a premium.

Inclusion Type Description
Feather A clarity inclusion that describes a break in the surface of a gemstone that extends inside. It is a common clarity characteristic that can occur naturally. Feathers can look transparent and almost be invisible. Or in certain angles and lights have a grayish or white appearance. Feathers that are more visible detract from the clarity of the diamond.Try to avaoid very large feathers that are near the surface or girdle of the diamond, as those can be more visible.
Crystal A clarity inclusion that forms during the diamond growth process within a diamond. It is used to determine the clarity grade. Crystals can exist in different colors within the diamond. Most commonly, they are found in black and white. White crystals are not always very distracting or visible. However, be careful if your diamond has black crystals, especially larger ones. These are obvious, even without magnification at times. Black crystals are the result of embedded carbon. Other colored crystals are far less common within diamonds.
Cloud A clarity inclusion that describes a group of tiny pinpoints within the diamond too small to individually distinguish under 10x magnification. A cloud can give a slightly hazy appearance where it is located within the diamond. Smaller coluds are typically not a major problem. When clouds cover a majority of the diamond area, they can cause an undesirable veil of haze that diminishes the sparkle. This is often hard to spot, however when looking at two magnified diamonds, one that is cloudy and another that is not, it is easier to see the difference.
Pinpoint A very small crystal inclusion that looks like a tiny dot at 10x magnification. Pinpoints are usually quite small ad require magnification to view.
Natural A small manufacturing remnant of the rough diamond skin that remains after the diamond cutting and manufacturing process. Naturals are typically located on or near the diamond's girdle.
Indented Natural A portion of a diamond's natural, rough skin that is left on a polished diamond during the manufacturing process in order to maintain diamond weight. It differs from a natural in that it is slightly protrudes inward. Typically indented natural can happen when a portion of the rough diamond is left unpolished during the cutting process. Indented natural can be found near the girdles of diamonds.
Needle A thin crystal that is visually needle-like and found inside the diamond. It is often as thick as a pinpoint but longer like a feather. Needles are typically white or transparent. Single needles are not as noticeable. However, in clusters or close together, needles can affect the clarity of the diamond negatively.
Knot A crystal inclusion that extends to the surface of a diamond. Larger knots are not desirable as they are very visible even without magnification.
Chip A chip is a small nick or opening that occurs on the surface of the diamond. This can happen on the edges of the diamond. Typically chips happen as a result of wear and tear or manufacturing accidents. Avoid diamonds that have large chips.
Cavity An opening created when part of a feather breaks away. This can happen when a diamond is being manufactured, as a small piece of it falls or breaks away as the diamond is being shaped. Small cavities are not typically a problem, however you should avoid larger cavities.
Twinning Wisp A clarity inclusion formed by a series of cloud, pinpoints or crystals. It may look like a large marking on a diamond plot, but is often difficult to see. Twinning wisps are the result of irregularites in the crystal structure of the diamond that occur as it is forming. Typically when diamonds are forming, specific environmental conditions are needed. When a diamond stops and starts regrowing the twinning wisps can form. Twinning wisps are a more desirable inclusion than crystals.
Internal Grading Lines sometimes visible under 10x magnification that result from irregular crystallization. Internal graining lines cannot be polished away and follow no particular pattern. They cross facet junctions. Graining is typically caused by uneven crystal growth within the diamond and can look like white or colored lines. When larger, they can also appear like bigger creases.
Surface Graining Transparent line-like formations on the surface of a diamond caused by crystal structure irregularities. Surface Graining can be difficult to identify even under magnification.
Etched Channel This is a narrow and small tunnel that is found on the diamonds surface and goes into the body of the diamond. This is a natural inclusion but can look similar to a internal laser drill treatment. This inclusion forms when diamonds are coming up to the surface of the earth. When judging the impact of the etched channel, look at the clarity grade of the diamond. This will help you understand how much of an impact the inclusions has on the diamond.

Below you can see examples off the most common inclusions on real diamonds. Remember that diamonds viewed under magnification will always appear to have displeasing inclusions. Always check with a With Clarity gemologist to see the impact of the inclusion on the actual beauty of the diamond.

Crystal Inclusion


Feather Inclusion


Cloud Inclusion


Twinning Wisp Inclusion

Twinning Wisp

Needle Inclusion


Pinpoint Inclusion


Knot Inclusion


Internal Graining Inclusion

Internal Graining

Sidestones & Accent Diamonds

One critical thing to look out for in jewelry purchases is the quality of sidestones and the accent diamonds, particularly in three stone rings or ones with larger accents. The jewelry must have gemologists inspect and carefully select matching stones. If they don't match, the jewelry looks odd and unappealing. Larger diamonds tend to have larger more visible inclusions so you need to ensure your accent stones match, partciularly with halo ring settings. The metal selection should not affect the choice of clarity as it pertains more to color.


Do sapphires hold their value over time?

Yes, sapphires do hold their value over time; just ensure to opt for a high-quality grade natural sapphire with an intense hue.

What is the value of a lab created sapphire?

A lab created sapphire will sell for a lower price compared to a natural sapphire, and usually costs approximately $40 per carat.