Diamond Inclusions to Avoid: Which Ones Actually Matter When Buying a Natural Diamond?

Nearly every natural diamond contains some form of internal characteristic. The mistake is assuming that every inclusion is undesirable—or that every diamond carrying the same clarity grade presents the same risk.

A tiny feather hidden inside a diamond may have virtually no effect on its appearance or suitability for jewellery. A dark crystal positioned directly beneath the table may be far more noticeable. A dense cloud can potentially reduce transparency without appearing as one obvious inclusion, while a surface-reaching characteristic close to a vulnerable corner may deserve attention for an entirely different reason.

This is why identifying the “worst diamond inclusions” by name alone is not a reliable buying strategy.

When assessing an individual natural diamond, four questions matter more: Can the inclusion be seen? Does it reduce transparency? Could its position create a durability concern? And where exactly is it located?

Those four questions tell you far more than simply seeing the word “feather”, “cloud” or “crystal” on a grading report.

Quick Answer: Which Diamond Inclusions Should You Avoid?

You should be most cautious about inclusions that create one or more of the following problems:

Visible inclusions: particularly dark, high-contrast or centrally positioned characteristics that are readily noticeable without magnification.

Transparency problems: extensive clouds, pinpoints, twinning wisps or graining that make the diamond appear hazy, milky, sleepy or less crisp.

Durability concerns: significant surface-reaching feathers, cavities, chips, knots or other characteristics positioned around vulnerable sections of the stone.

Unfavourable locations: inclusions underneath the centre of the table, against very thin girdle areas or close to exposed corners and points.

That does not mean every feather, cloud, cavity, crystal or pinpoint should automatically be rejected.

A small feather completely enclosed within a diamond can be harmless. A minor cloud may have no visible effect. A tiny crystal near the perimeter may be considerably preferable to a similarly sized dark crystal under the table.

The correct rule is:

Avoid the effect, not simply the inclusion name.

Diamond Inclusions: Risk at a Glance

This table should be treated as a screening framework rather than a grading system. The severity of an inclusion depends on its size, number, position, contrast and relationship with the rest of the diamond.

What Is a Diamond Inclusion?

A diamond inclusion is an internal clarity characteristic, or a characteristic that extends into the diamond from its surface.

Natural diamonds form under immense geological conditions, so internal characteristics are completely normal. They can include crystals, pinpoints, feathers, clouds, needles, twinning wisps, knots and other features.

Diamond clarity grading does not simply count these characteristics. The impact of an inclusion depends on factors such as its size, nature, number, position and relief—or how strongly it contrasts with the surrounding diamond.

That is why two diamonds with the same VS2 or SI1 clarity grade can behave very differently.

One VS2 might contain several tiny pale inclusions that disappear during normal viewing. Another may contain one darker characteristic in a visually prominent position.

The grade tells you the general level of clarity. It does not tell you whether you personally will like the inclusion pattern.

The Four Ways an Inclusion Can Become a Problem

Rather than memorising a long list of inclusion names, buyers should examine four practical risks.

1. Visibility

The first question is straightforward: Can you actually see it?

A tiny inclusion that requires substantial magnification to locate will normally have very little effect on everyday appearance. A dark crystal positioned directly underneath the table may be considerably easier to notice.

Visibility depends on more than size. Contrast, colour, position, diamond shape and the surrounding facet pattern can all change how obvious an inclusion appears.

A small dark crystal may attract more attention than a larger transparent characteristic because it creates stronger contrast with the surrounding diamond.

This is particularly important for engagement-ring centre stones because the wearer may examine the diamond closely every day.

2. Transparency

Some clarity problems are not experienced as a visible spot.

Instead, the entire diamond—or part of it—can appear less transparent.

Dense clouds, extensive groups of pinpoints, significant twinning wisps or certain forms of graining can sometimes create a hazy, milky or sleepy appearance.

This distinction is important because a diamond could technically appear “eye-clean” in the sense that you cannot identify one individual inclusion, yet still look less crisp than a comparable stone because its transparency has been affected.

When comparing diamonds, do not ask only whether you can see an inclusion.

Also ask:

Does the diamond itself look clear, lively and transparent?

3. Durability

Diamond is extremely hard, but hardness does not mean that a diamond is impossible to chip.

Certain clarity characteristics deserve additional attention when they break the surface or occur near structurally vulnerable parts of a polished diamond.

A substantial feather reaching the surface near a girdle, a cavity, an existing chip or a characteristic close to a pointed tip can deserve more attention than an inclusion safely enclosed within the interior.

This does not mean every surface-reaching characteristic makes a diamond unsuitable.

It means the characteristic should be evaluated in the context of its size, location and intended setting rather than approved through clarity grade alone.

4. Location

Location can completely change the significance of an inclusion.

Imagine two diamonds containing similar dark crystals. In the first diamond, the crystal sits close to the outer edge and becomes difficult to identify amongst the facet reflections. In the second, it sits directly underneath the centre of the table.

The laboratory grade may be similar, but the buying experience can be completely different.

Similarly, an inclusion near the perimeter may be visually unobtrusive but require closer attention if it lies close to a thin girdle, corner or point.

An inclusion's position therefore needs to be considered from both a visual and structural perspective.

Dark Crystals: When Should You Avoid Them?

Dark crystals are among the characteristics buyers notice most quickly because they contrast strongly against the transparent diamond.

You may occasionally hear these described commercially as “black carbon spots”. That terminology can be misleading because it is not a formal clarity-characteristic category used on a grading report. The more useful question is whether the stone contains a dark, high-relief crystal and where that crystal is located.

A very small dark crystal near the perimeter may remain difficult to see without magnification. A larger dark crystal directly beneath the table can be far more distracting.

For a centre stone intended for an engagement ring, a readily visible dark crystal underneath the table is one of the inclusion patterns we would scrutinise most carefully.

The decision should become stricter as the stone becomes larger or as the diamond shape provides a clearer view into its interior.

Central Inclusions: Location Can Be More Important Than Type

The table is the large central facet on the top of many polished diamonds. Characteristics positioned beneath this area can receive greater visual attention simply because the viewer has a more direct view into the stone.

This is why a central inclusion can sometimes be less desirable than a technically similar characteristic near the perimeter.

The issue becomes especially important when the inclusion is dark, large, reflected several times by the facet arrangement or sits in an otherwise very clean-looking diamond.

However, “under the table” does not automatically mean reject the stone.

A tiny transparent pinpoint or very low-relief inclusion may remain impossible to identify without magnification.

Again, visibility is the deciding factor—not the diagram alone.

Feather Inclusions: Are They Dangerous?

Feathers are one of the most misunderstood diamond inclusions.

A feather is a break within a gemstone that may appear white, transparent or reflective depending on the viewing angle.

Many diamonds contain small feathers that have no meaningful effect on appearance or everyday wear. A tiny feather completely enclosed within the diamond should not automatically concern a buyer.

The situation deserves more attention when the feather is large, reaches the polished surface, approaches the girdle or occurs around a vulnerable corner or pointed end.

A surface-reaching feather in a large pear-shaped diamond, for example, deserves different consideration from a tiny internal feather in the pavilion of a round brilliant.

The word “feather” on a grading report is therefore not enough information to reject a diamond.

You need to know its size and location.

When Should You Be Cautious About a Feather?

A feather deserves closer examination when it:

• reaches or opens onto the surface;
• extends across a substantial portion of the stone;
• lies close to a very thin area of the girdle;
• approaches a princess-cut corner;
• occurs close to a pear or marquise point;
• appears visually distracting face-up;
• could be affected by pressure during setting.

These conditions do not automatically prove that the diamond is unsafe. They mean that the stone deserves individual professional inspection before purchase or setting.

A small, internal, low-relief feather can be entirely different.

Cloud Inclusions: The Real Risk Is Transparency

A cloud is a group of tightly clustered pinpoints that may be too small to distinguish individually.

The word “cloud” often worries buyers unnecessarily. A small cloud in an otherwise high-quality diamond may have no visible effect whatsoever.

The concern arises when clouds become extensive or dense enough to reduce transparency.

Instead of seeing a distinct black or white inclusion, you may notice that the diamond appears slightly hazy, milky or less crisp than another stone with similar cut and colour specifications.

This can be particularly important in lower clarity ranges where clouding contributes significantly to the clarity grade.

The practical buying test is not simply:

“Does the grading report mention a cloud?”

It is:

“Does this particular cloud affect the diamond's transparency or visual performance?”

If the stone looks bright, transparent and clean, a small cloud is not necessarily a reason to reject it.

“Clarity Grade Based on Clouds Not Shown”: What Should You Do?

Grading reports sometimes include comments indicating that clouds or other characteristics are not completely shown on the plotting diagram.

This should not automatically be interpreted as a bad diamond.

However, when a lower-clarity stone relies heavily on widespread characteristics that are not represented individually on the plot, visual inspection becomes especially important.

Compare the diamond against another stone with similar cut and colour under consistent lighting. Check whether the first diamond appears equally crisp and transparent.

If it looks noticeably hazier despite otherwise attractive specifications, the apparent discount may not represent genuine value.

A lower price is useful only when the diamond still looks good.

Cavities: Why They Deserve Closer Inspection

A cavity is an angular opening that can occur when part of a surface-reaching crystal is removed or breaks away.

Unlike a completely enclosed internal crystal, a cavity involves the polished surface of the diamond.

That alone does not tell you whether the cavity is severe, but it means the characteristic should receive closer inspection.

Consider its size, position and whether it sits in an area likely to be exposed during everyday wear or setting.

For an important centre stone, we would generally prefer a similarly priced diamond without a significant cavity when all other specifications and appearance are comparable.

That is a genuine quality distinction—not simply a desire for a higher clarity grade.

Knots: What Does a Knot Mean in a Diamond?

A knot is a crystal contained within the diamond that extends to the polished surface.

A small knot does not automatically make a diamond unsuitable, but because the characteristic interacts with the surface, it deserves more attention than an isolated internal pinpoint.

Inspect whether the knot can be detected visually, where it reaches the surface and whether the proposed setting places pressure near that area.

As with cavities and surface-reaching feathers, the correct response is careful assessment rather than automatic rejection.

Chips: Existing Damage Is Different From a Natural Inclusion

A chip is a shallow opening created by damage to the diamond's surface, often around an edge, facet junction or culet.

This is different from simply having a natural internal inclusion.

An existing chip should therefore be treated as a condition issue and examined very carefully.

For a newly purchased centre diamond, an obvious chip normally provides a stronger reason for caution than harmless internal inclusions of similar visual size.

The location of the chip matters as well. Damage around a thin girdle, corner or pointed end may require different handling during setting.

Needles and Pinpoints: Often Less Concerning Than They Sound

A pinpoint is an extremely small crystal that appears like a dot under magnification. A needle is a narrow, elongated crystal that resembles a tiny rod.

Small pinpoints and needles are common examples of characteristics that can sound more concerning on paper than they appear in the actual diamond.

When minor, low contrast and well positioned, they may have virtually no effect on face-up appearance.

Several tightly grouped pinpoints can form a cloud, which means the overall pattern matters more than any individual pinpoint.

A single tiny pinpoint is therefore very different from an extensive group of pinpoints affecting transparency.

Twinning Wisps: Do You Need to Avoid Them?

A twinning wisp can consist of pinpoints, clouds, crystals or other features associated with the diamond's growth structure.

Twinning wisps are not automatically undesirable.

A minor wisp may be extremely difficult to notice and have little effect on appearance. More extensive wisps, however, can deserve closer scrutiny if they cross a large part of the diamond or contribute to reduced transparency.

The decision should therefore depend on actual appearance and extent rather than the presence of the term on the report.

Internal Graining: When Does It Matter?

Internal graining results from irregularities in the crystal-growth structure of the diamond and can appear as lines, angles or other internal patterns.

In many stones, the effect is extremely subtle.

When extensive, however, graining can influence transparency or create visible internal structure.

This again illustrates why clarity should never be reduced to a simple list of “safe” and “unsafe” inclusion names.

A minor characteristic may be harmless. A more extensive version of that same characteristic may materially affect the stone.

Should You Avoid an SI1 Diamond With Inclusions?

No—not automatically.

A carefully selected SI1 natural diamond can represent excellent value, particularly in round brilliants and other brilliant-style shapes.

The right SI1 can appear eye-clean, retain strong transparency and contain characteristics in unobtrusive locations.

The wrong SI1 can contain a visible dark crystal, a problematic surface-reaching characteristic or widespread inclusions that make the stone look hazy.

That is precisely why clarity grade alone cannot determine value.

A strong SI1 can be a better purchase than an unattractive VS2. Conversely, paying slightly more for VS2 can be worthwhile when the available SI1 stones do not meet the required visual standard.

Internally link this section to Best Diamond Clarity for an Engagement Ring.

Can a VS2 Diamond Still Have an Inclusion You Should Avoid?

Yes.

VS2 is a high and highly useful clarity grade, but it is not an automatic guarantee that every buyer will approve every stone.

One VS2 might contain several tiny characteristics that are practically impossible to notice in ordinary viewing. Another might contain a darker crystal in a visually sensitive location.

Surface-reaching characteristics should also be reviewed independently of the headline grade.

That does not make VS2 risky. It simply reinforces the principle that clarity grade is a range, while you are purchasing one specific diamond.

For a detailed grade comparison, internally link to Dalila’s VS1 vs VS2 Diamond Clarity guide.

Which Inclusion Locations Deserve the Most Attention?

The significance of location changes according to the diamond shape.

Directly Under the Table

Central inclusions can be easier to notice, particularly when they have strong contrast or are reflected by several facets.

This location is primarily a visibility concern.

Near the Girdle

A small inclusion around the perimeter may be visually favourable because it is harder to see face-up.

However, surface-reaching features near the girdle can deserve closer inspection from a condition and setting perspective.

This means an edge inclusion can be visually better yet structurally more important.

At a Pear-Shaped Diamond's Point

The pointed end of a pear deserves protection during setting and wear. A significant feather or surface-reaching feature in this area should therefore be assessed carefully.

At a Marquise Point

The same principle applies to both ends of a marquise diamond.

Characteristics positioned close to either point deserve more scrutiny than a harmless inclusion safely enclosed elsewhere.

At Princess-Cut Corners

Princess diamonds have pointed corners that normally require appropriate setting protection.

A significant inclusion close to one of those corners should therefore form part of the purchasing decision.

Beneath a Prong

You may hear that an inclusion can simply be “hidden by a prong”.

That can sometimes be visually useful, but it is not a universal solution.

A setter should not be asked to place pressure directly on a vulnerable characteristic simply because the prong conceals it.

The setting must be planned around the actual condition of the stone.

Does Diamond Shape Change Which Inclusions Are Acceptable?

Yes.

Brilliant-style diamonds such as round, radiant and many cushion cuts use complex facet structures that can help disguise certain minor characteristics.

Step-cut diamonds such as emerald and Asscher cuts provide a clearer, more open view into the interior.

As a result, a small inclusion that remains difficult to see in a round brilliant may be easier to identify in an emerald cut.

Larger facets can also make central characteristics more apparent.

Therefore, the inclusion pattern that represents excellent value in one shape may not be the best choice in another.

The grade has to be interpreted through the facet structure.

Does Carat Weight Make Inclusions More Visible?

Often, yes.

As the physical dimensions of a diamond increase, there is more surface area to examine and individual facets may become larger.

This can make certain characteristics easier to notice.

A VS2 inclusion pattern that looks completely unobtrusive in a 0.70 carat round diamond should not automatically be assumed to behave the same way in a 3 carat centre stone.

Larger diamonds deserve stronger scrutiny through high-resolution video, realistic viewing scale and the grading report.

This does not mean large diamonds always require VVS clarity. It means individual inclusion quality becomes increasingly important.

Can an Inclusion Affect Diamond Sparkle?

Minor inclusions do not automatically reduce sparkle.

A diamond's light performance is primarily influenced by cut quality, proportions and facet relationships.

However, extensive inclusion patterns that materially reduce transparency can prevent a diamond from looking as crisp and lively as an otherwise comparable stone.

This is why a clean-looking inclusion plot cannot replace visual inspection, and why a busy-looking plot does not automatically indicate poor performance.

What matters is whether the characteristics actually interfere with the appearance of the diamond.

Do Diamond Inclusions Get Worse Over Time?

Most internal inclusions do not simply grow or spread because the diamond is being worn.

However, an existing vulnerability can become relevant if the diamond receives an impact in an unfavourable location.

That distinction matters.

A tiny, entirely enclosed crystal is not expected to suddenly expand simply because the stone is worn in a ring. A chipped edge or significant surface-reaching break, on the other hand, deserves more consideration because the physical condition of that area is already different.

The best approach is to evaluate potentially vulnerable characteristics before the diamond is set and ensure that the setting provides appropriate protection.

How to Check Diamond Inclusions on a Grading Report

The grading report should be treated as the first layer of inspection rather than the final decision.

Where a clarity plot is provided, identify the characteristics shown and look at where they are positioned. Pay particular attention to dark or large characteristics beneath the table and surface-reaching features near girdles, points and corners.

Then review the comments section. Some relevant characteristics may be mentioned in the comments rather than individually plotted.

Next, compare the report against high-resolution images and video of the actual diamond.

A grading plot is a diagram. It cannot fully communicate contrast, transparency or naked-eye appearance.

Finally, examine the stone at a realistic scale. Magnification is essential for understanding the inclusion, but an enormous video can make a harmless characteristic look much more serious than it appears during ordinary wear.

Internally link this section to Dalila’s Diamond Grading Report Guide.

The Dalila Diamond Inclusion Decision Framework

Instead of rejecting a diamond because the report says “feather” or “cloud”, evaluate the characteristic in a consistent sequence.

First, determine visibility. Look at the diamond face-up at a realistic size and decide whether the inclusion distracts you without magnification.

Next, check transparency. The stone should look crisp and lively rather than hazy, sleepy or milky.

Then review location. An inclusion beneath the table creates a different concern from one at the perimeter, while a characteristic close to a point or corner deserves additional structural attention.

After that, determine whether the feature reaches the surface. This is particularly relevant for feathers, cavities, knots and existing damage.

The intended setting should then be considered. Points, corners and thin girdle areas may require appropriate protection.

Finally, compare the diamond with alternatives in the same price range. A discounted stone is not automatically good value simply because it is cheaper. If a modest increase in price buys a cleaner, more transparent or better-positioned inclusion pattern, that may be the better purchase.

Diamond Inclusion Red Flags Before Buying

There are several situations where we would slow the purchase down and inspect the stone much more carefully.

A dark inclusion that is immediately visible beneath the table deserves attention because it may become the feature your eye continually notices.

A diamond that appears hazier or less transparent than comparable stones should also be questioned, even when you cannot identify one obvious inclusion.

Significant surface-reaching feathers, cavities, knots and existing chips should be evaluated for their position and extent rather than dismissed because the overall clarity grade appears respectable.

Characteristics positioned close to pear or marquise tips, princess corners or vulnerable girdle areas require particular care before setting.

Finally, be cautious when the actual diamond does not visually support the grading report impression. The report tells you the grade. Your inspection tells you whether you want that specific stone.

Diamond Inclusions That Can Actually Offer Better Value

Not every inclusion should be treated as a disadvantage.

Some of the best-value natural diamonds contain characteristics that influence the laboratory grade but have almost no effect on normal appearance.

A small pale crystal near the perimeter, tiny enclosed feather, isolated needle or low-relief pinpoint can sometimes allow a buyer to obtain a lower clarity grade while maintaining an effectively clean face-up appearance.

That creates an important value opportunity.

Instead of paying for a microscopic upgrade from VS2 to VS1 or VVS, the buyer may be able to allocate more budget towards cut, dimensions, carat weight or another visibly important specification.

The objective should therefore never be “find a diamond with no inclusions”.

It should be:

Find a diamond whose inclusions do not meaningfully reduce its beauty, transparency, durability or suitability for the intended jewellery.

Common Mistakes Buyers Make With Diamond Inclusions

One of the biggest mistakes is rejecting every feather. Small internal feathers can be completely acceptable, while the location and extent of the feather are far more important than its name.

Another mistake is assuming every cloud makes a diamond milky. Minor clouds can be visually irrelevant. Dense or extensive clouding is what deserves closer scrutiny.

Buyers also frequently focus on a crowded clarity plot without checking whether the characteristics are actually visible. Several tiny, low-relief inclusions can sometimes be less distracting than one dark central crystal.

The opposite mistake is relying too heavily on the phrase “eye-clean”. A diamond may have no individually visible inclusion yet still suffer from reduced transparency.

Finally, buyers sometimes assume that a prong can hide every edge inclusion. A prong can conceal a characteristic visually, but it should not be used to ignore a potential structural issue.

Final Answer: Which Diamond Inclusions Should You Actually Avoid?

There is no single inclusion type that should automatically eliminate every natural diamond containing it.

Instead, avoid problematic inclusion patterns.

Be particularly cautious with clearly visible dark or central characteristics, significant clouds or other features that reduce transparency, surface-reaching characteristics that may create a condition concern, existing chips and inclusions positioned around vulnerable corners, points or girdle areas.

By contrast, tiny pinpoints, needles, pale crystals, minor enclosed feathers and small clouds can often be completely acceptable when they remain unobtrusive and do not affect transparency or durability.

The best natural diamond is therefore not necessarily the one with the highest clarity grade or the emptiest inclusion plot.

It is the diamond whose natural characteristics allow it to remain visually clean, transparent, structurally appropriate and correctly priced for its quality.

That is the difference between buying a clarity grade and selecting a diamond.

Compare Natural Diamonds by More Than Clarity Grade

Dalila Diamonds allows buyers to compare certified natural diamonds according to shape, carat, colour, clarity and other grading characteristics.

Rather than automatically excluding every diamond containing a feather, cloud or crystal, compare the actual inclusion pattern and determine whether it has any meaningful effect on the stone.

If the precise combination you require is not currently available, DS4U – Diamond Source For You can be used to source natural diamonds according to the required shape, carat, colour, clarity, cut and budget.

Where applicable, S2S – Secure To Source can support buyers who have already identified a diamond and require additional sourcing, quality-control, euro-payment or delivery coordination for confirmed destinations.

Frequently Asked Questions About Diamond Inclusions