You know the saying, 'It's what's on the inside that counts'? Well, the phrase has never been more accurate when referring to diamonds!

Much like every human you’ve ever met, every diamond has its little quirks - in the gem world, we call these 'inclusions.' 

They're like nature's birthmarks, nestled deep, near the surface, and sometimes on the surface of a diamond, making each one as unique as your fingerprints.

Sure, you've heard whispers about 'flawless' diamonds. Just like the perfect partner or a spotless kitchen countertop, the idea of “flawless” is more myth than reality. 

In this sparkle-packed guide, we'll give you the inside scoop on inclusions – from the quirky to the charismatic – and how they make your diamond stand out. 

What Are Diamond Inclusions?

Diamond inclusions are internal characteristics formed deep within the Earth under extreme heat and pressure conditions. 

These characteristics can include internal fractures, known as feathers, or small foreign crystals, such as garnets or other minerals, that were absorbed into the diamond during its growth process. 

They are the natural birthmarks of a diamond, providing a unique fingerprint that tells the story of its long journey from the depths of the Earth to the surface.

Inclusions vs Blemishes

In a diamond, an inclusion is something inside the stone, like a tiny crystal or cloud, while a blemish is a flaw on the surface, such as a scratch or chip.

Both affect the diamond's clarity grade but differ in where they're found: inclusions are inside, and blemishes are on the surface.

Role in Distinguishing Natural from Synthetic Diamonds

Inclusions are one of the primary features that gemologists use to distinguish natural diamonds from synthetic ones. 

Synthetic or lab-grown diamonds may also have inclusions, but these are often different in type, location, and appearance compared to those found in natural diamonds. 

Identifying these inclusions is crucial in the gem trade for authenticity and historical and geological research, as they provide insights into the natural diamond formation process.

Determining Diamond Quality

The presence and characteristics of inclusions are essential factors in determining a diamond's quality. 

While clarity is only one of the four Cs of diamond grading (alongside color, cut, and carat weight), it is vital in assessing a diamond's overall quality and value. 

Inclusions affect how light is reflected and refracted within the diamond, influencing its sparkle and brilliance. 

While too many inclusions can detract from a diamond's beauty, some can be hidden by a skilled jeweler's placement of the prongs when setting the diamond. 

In essence, inclusions play a crucial role in defining each natural diamond's individuality and authenticity, contributing to its narrative and desirability.

Diamond Inclusion Grading 

The Gemological Institute of America (GIA) uses a clarity grading scale based on factors like size, type, location, and visibility under 10x magnification to determine the overall clarity grade of a diamond, which are:

• Flawless (FL): No visible inclusions or blemishes under 10x magnification.
• Internally Flawless (IF): No inclusions, only insignificant surface blemishes visible under 10x magnification.
• Very Very Slightly Included (VVS1, VVS2): Minute inclusions difficult for a skilled grader to detect under 10x magnification.
• Very Slightly Included (VS1, VS2): Minor inclusions that are visible under 10x magnification but considered difficult to see for an untrained eye.
• Slightly Included (SI1, SI2): Noticeable inclusions that are fairly easy to see under 10x magnification.
• Included (I1, I2, I3): Inclusions visible to the naked eye, affecting transparency and brilliance of the diamond.

Each grade reflects increasing levels of inclusions, with characteristics such as crystals, feathers, clouds, or needles being assessed for size, quantity, and nature to determine the final clarity grade, significantly influencing the value and visual appeal of the diamond.

Types of Diamond Inclusions

Bearding

Ever seen a diamond with a bit of a 5 o'clock shadow? 

We’re joking!

Or are we? 

Bearding refers to very fine, hair-like lines that can appear on a diamond - usually manifest from its girdle, stretching to its surface.

Diamond bearding can be a faint stubble to a full-blown heavy beard. A diamond with heavy bearding might look like it hasn’t bothered to shave in weeks!

While diamond bearding might give your diamond a rugged charm, these lines can also affect how the edges vibe with the light.

A once bright and shimmering gem may look gray and dull. 

The heavier the “beard,” the more scratched your diamond will appear to the naked eye.

Cavity

Nope, diamonds can get cavities too. And not because they’ve been sneaking candy between meals!

Diamond cavities map the crafting journey your diamond took. Like an all too painful tooth cavity, diamond cavities are often big openings on the surface that might catch more than the light - dirt.

Sadly, any dirt caught in your diamond will affect your bling's blinding brilliance.

Why doesn’t the diamond cutter just scale and polish the cavities?

If they did, they’d have to sacrifice extra weight to even out the diamond’s surface - and with less weight comes a lower price tag.

Keeping the dental analogy rocking would be like removing a chipped tooth without replacing it.

Lower clarity (appearance), but a heavier weight fetches more value. 

Therefore, most diamond cutters will keep the cavities. It isn’t bad; it often means that buyers can purchase a heavier-weighted diamond at a lower cost. 

You can often barely notice the cavities - especially if you care for your diamond and maintain regular cleaning from a diamond professional.

Chip

Unfortunately, these diamond inclusions don’t come with a free bag of potato chips.

Chips are the inclusions that result from your diamond living its life.

A chip is a tiny nick on the surface, a testament to your gem's adventures and stories it could tell if only it could talk!

Thankfully, diamond chips don’t go shouting around town, and they are often concealed by the diamond’s facet junctions, the girdle, or its cutlet. 

Cloud

Imagine a tiny cloud trapped forever in your diamond. 

Romantic, right? 

Diamond clouds are as varied as the fluffy ones in the sky.

A small, wispy cloud on a backdrop of a clear blue sky might not spoil your trip to the beach.

An ominous and all-consuming cloud blocking the sunlight might make you rethink your plans.

These clusters of pinpoints or crystals in your diamond create a soft, hazy look inside your stone. In some, it’s a whisper of mist; in others, a thick fog rolling in.

Unsurprisingly, your diamond’s weight and size will determine whether you need extra attention to your inclusions. 

Thankfully, the GIA provides an incredibly detailed map of any disruptors to your diamond’s clarity - including any cloud threatening your sparkle. 

If there are a few clouds or they are “diffused,” you have very little to be worried about. If they are bunched together or are dense in appearance, then light may have a tougher time shining through.

Crystal

These are like snowflakes caught in a winter freeze right inside your diamond. 

Crystals are precisely what they say they are: Crystals.

These minerals are nature’s extra sprinkle, but on the face of it, these sprinkles aren’t always desired. The crystals could be anything from carbon, garnets, or peridots (and then some!). 

Each crystal comes packed with extra color, some examples include:

• Carbon (Black)
• Garnet (Red)
• Peridots (Green)

But don’t people pay for these colored gems?

Yes, when they’re in the market for rubies, sapphires, emerald…the list goes on.

For those purchasing a pure diamond, these hues created by additional mineral crystals can change the diamond’s color and appearance.

Depending on their density, these mineral crystals can be a secret only you know or a visible twinkle that adds to your diamond's story.

Most people would rather avoid crystal inclusions and edge towards a purer, white color synonymous with diamonds. 

Feather

These inclusions are small cracks in a diamond that we lovingly call feathers. 

Why? 

Because 'crack' or ‘fracture’ sounds so harsh for something that adds such a fascinating detail to your gem. Not to be confused with real feathers, though!

You might not even notice feather inclusions depending on how detailed your eye is for diamonds.

They are mostly transparent, but if you view your diamond from different angles, you may see their faint feathered appearance whispering through your stone. 

And watch out - these feathers can affect how tough your diamond is. One feather isn’t much to worry about, several? They begin threatening your diamond’s structure and durability. 

Be cautious of any feather inclusions too close for comfort in the diamond’s girdle. Give your gem a good scan in various light settings, too.

The inclusions are also likely too severe if the feathering affects the diamond’s color.

Graining

Grains in wood are signs of character and age, and it's no different for diamonds. 

Graining happens because the diamond grew underground, showing up as faint lines or streaks that give your diamond a fingerprint.

Unlike standard crystal inclusions, graining is defined by the irregularity of the crystal growth.

Their composition inside your diamond can produce milky or hazy coloration, blocking light from passing through the gem.

Less severe graining can manifest as faint lines or slight streaks in places, but the heavier the graining, the more prominent their presence.

Diamond experts refer to these diamonds as having “creases.” 

Sometimes, they are defined as reflections, stealing the stage from your diamond’s fundamental reflective qualities.

Indented Natural

Some diamonds have rougher backstories than others!

Indented natural inclusions refer to a piece of the diamond's original rough coat that stuck around after the cutting and polishing.

It’s a reminder of where it came from, proudly wearing a piece of its history. You will likely find these inclusions around the girdle if you want to locate them. 

Again, always consult a reputable diamond seller and ask for your diamond’s certification report to get the full low-down.

Knot

Not to be confused with tying the knot, though these inclusions might be good luck if you get hitched with one!

Knot inclusions are actual crystals that have worked their way to the surface.

They might change a facet's look, but they’re proof of your diamond's journey from the depths of the earth to your jewelry box or ring finger.

They are usually white and colorless, which is a bonus - but they do shimmy to facet surfaces, which may be considered undesirable to some. 

Needle

Don’t worry; these needles won’t cause you any pain!

Needle inclusions are generally long and thin and sometimes look like a miniature column inside your diamond.

If they bunch up, they might affect clarity, but they're mostly just chilling in there, adding to the mix.

You’d have to zoom in using 10x magnification to see them in all their glory, but given their effect on clarity, some view them as a big no-no. 

Pinpoints

Another one for the 10x magnification!

Pinpoints are tiny black or white crystals often invisible to the naked eye, like the stars in the night sky of your diamond (but during daylight). 

You'll need a magnifying glass to spot these correctly, but they're easier to notice by the trained eyes of diamond aficionados.

Twinning Wisps

When a diamond grows in a new direction, it leaves behind twinning wisps - patterns that tell the tale of its life under the Earth's surface. 

Twinning wisps are the diamond inclusion besties - bringing together the pinpoints, clouds, and crystals gang for a party. They're the history lines in your gem's life story. 

In a diamond’s younger years, it might take a break from growing if the environmental conditions aren’t tip-top. When it starts growing again (not anytime fast, may we add, sometimes up to 1000 years later), it might take a new direction.

When its growth direction alters, the twinning wisps become the remnants of the diamond’s journey.

Don’t diminish, though - it’s been through a lot!

Evaluating the Impact on Diamond Value

Now you understand the different inclusions, you’re probably questioning how they impact a diamond’s value.

We’ve somewhat traversed what’s acceptable and what’s not when it comes to diamond inclusions, but let’s take a whistle-stop tour through diamond clarity grading.

When assessing a diamond's clarity grade and value, four key factors come into play: size, quantity, placement, and visibility of inclusions. 

As we now know, inclusions are natural characteristics, often microscopic, formed when the diamond was created deep within the Earth.

But that doesn’t mean they’ll go unnoticed by diamond graders!

Inclusion Size: 

The larger the inclusions, the more they can impact the clarity of a diamond. More prominent inclusions can disrupt the light flow through the diamond, affecting its brilliance and value.

Large inclusions can also disrupt your diamond’s structure and durability.

If you’re curious about the impact of your diamond’s inclusions, speak with your trusted jeweler or chat with our diamond experts online!

Inclusion Quantity: 

A higher number of inclusions typically means a lower clarity grade. More inclusions can make a diamond appear less clear and sparkling.

If they’re bundled, the light must battle to get through the diamond, often failing in its efforts.

Less sparkle and light = lower clarity grade.

Inclusion Placement: 

Where these inclusions are located is crucial!

Inclusions near the center or top of a diamond are more visible and can impact the stone's appearance more than those at the sides or bottom. 

Inclusion Visibility: 

This is the most critical factor.

Inclusions visible to the naked eye (without magnification) significantly reduce a diamond's clarity grade and value.

The less visible the inclusions, the higher the clarity grade and, hence, the value.

Genuinely flawless diamonds, those without any inclusions or blemishes visible under 10x magnification, are exceedingly rare.

This rarity contributes significantly to their value.

Most diamonds have some inclusions, but the interplay of these four factors determines how these inclusions affect the overall clarity grade and value.

Inclusion Conclusion

Every diamond is unique, and inclusions aren’t always make or break.

The inclusions make each diamond distinct, and their uniqueness should be celebrated.

Always check your diamond’s certification report, but it’s essential to consider personal preferences and the stone's overall appearance. 

You may prefer the pristine nature of a flawless diamond or find beauty in the one-of-a-kind inclusions of a slightly less-than-perfect stone. 

Remember, a diamond's worth isn't solely based on its clarity grade but also on the story it tells and the connection it holds with its owner. 

Your perfect diamond is the one that resonates with you, capturing your imagination and symbolizing your unique story.

Are you in need of a diamond expert?

Ben Garelick is here to guide you towards a glittering abyss of sparkling diamonds. Grab a glass of bubbly with us at our showroom or chat with our diamond experts online.

Peter Manka Jr. - Owner at Ben Garelick

Peter Manka Jr. is a passionate member of the family business who joined Ben Garelick in the early 2000s after working in product licensing for Sesame Workshop & The Jim Henson Company for many years. He obtained a degree in diamonds and jewelry from the prestigious Gemological Institute of America (GIA) in order to sharpen his jewelry skills. He takes great pride in providing exceptional customer service and helping clients find the perfect piece of jewelry.