Diamond Inclusions Guide: What Are Diamond Inclusions?
Diamond inclusions have oftentimes been portrayed as the hallmark of a diamond’s imperfection and as the main reason for a cloudy appearance. Inclusions determine a diamond’s clarity grade and can impact its appearance and value. But they are largely unavoidable. Inclusions are a foundational and natural characteristic of a diamond and a great marker of its identity.
Understanding what inclusions are and the different types of inclusions will help you make an informed decision when choosing a diamond. Read on to learn how to buy a beautiful diamond based on their inclusions and clarity characteristics.
What Is a Diamond Inclusion?
Diamond inclusions are small imperfections within a diamond. Inclusions are formed because of the tremendous heat and pressures needed in the diamond creation process.
Diamond inclusions are small imperfections within a diamond. Inclusions are formed because of the tremendous heat and pressures needed in the diamond creation process.
Inclusions vs. Blemishes
Both inclusions and blemishes are “imperfections” in a diamond that influence its overall appearance and clarity grade. But inclusions and blemishes are not the same thing. Inclusions refer to a diamond’s internal compositional flaws while blemishes refer to any external flaws on the diamond’s surface.
What Causes Inclusions in Diamonds?
During the formation process of diamonds, small crystals can become entrapped in the carbon grid. Sometimes, that crystal grows and develops, forming an inclusion called grain lines.
Inclusions are what make a diamond unique. Just like no two people have the same fingerprints, the same can be said about diamonds and inclusions. A diamond’s inclusion can be a great identifier. They can be a feature, not a flaw.
Do Diamond Inclusions Matter?
Inclusions do matter. Inclusions are an essential factor when it comes to determining a diamond’s clarity, which is one of the diamond 4Cs. As such, inclusions impact a diamond’s overall value. Slightly included diamonds can still be valuable and very desirable depending on their otherh characteristics.
While most diamonds have inclusions, the type and location of the inclusion will determine how much it impacts a diamond's overall appearance.
Types of Diamond Inclusions
Not all inclusions are the same. Inclusions can be reminiscent of small indentations, hairline fractures, darker dots, cloud-like formations, patches of color, or thin needles.
Different-looking inclusions are different types of inclusions. Diamond inclusion variations will influence how they affect a diamond’s appearance and clarity grade. You can find the different diamond inclusion types below.
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Bearding : Bearding consists of hair-like lines that extend from the girdle into the surface of the stone. They are a result of the cutting process of a diamond. Heavy bearding will give a diamond a cloudy and fuzzy appearance.
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Cloud : In terms of diamond inclusions, a cloud consists of tightly grouped pinpoints (at least three) that might be too small to distinguish individually but together have a hazy appearance. They do not affect the durability of the stone.
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Crystal : A crystal is another mineral included in a diamond. A crystal can be colorless when another diamond is embedded within the diamond. It will be black in the case of carbon, reddish in the case of garnets, or greenish in the case of peridots.
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Feather : A feather is a break in the diamond, and its name derives from its feather-like appearance. Feathers are a type of inclusion you need to pay attention to. Depending on their location, they can make a diamond more prone to chipping and cleaving.
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Internal Graining : Graining is an irregular internal crystal growth with a milky or hazy appearance. It can also sport faint lines or streaks.
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Knot : A knot is an included diamond crystal that extends to the surface. Unlike the crystal inclusion, a knot affects the durability of the diamond.
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Needle : A needle is a type of rod-shaped crystal inclusion occurring in a diamond.
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Pinpoint : A pinpoint is a tiny white or black inclusion, only a few micrometers in size.
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Twinning Wisp : Twinning wisps are veils of tiny needles, clouds, pinpoints, and crystals running along the diamond's twinning plane, caused by growth distortion.
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Indented Natural : Indented naturals are internal markings or grooves, often triangular, that are caused when part of the crystals from a rough diamond’s surface sinks beneath during formation.
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Bruise : A bruise is a small area with tiny feathers extending from it, creating a cotton-like texture.
Are Inclusions Visible to the Eye?
Most inclusions are only detected through 10x magnification and are still considered eye-clean. The visibility of an inclusion depends on size and placement. For example, a carbon inclusion on a VS2 diamond at the center of its table is more visible than a crystal inclusion on the crown near the girdle in a SI1 diamond.
Certain diamond shapes and diamond cuts will also determine how visible an inclusion is to the naked eye. Brilliant cut diamonds will hide inclusions better than step cut diamonds.
In addition, carat size affects the visibility of inclusions. The higher the carat weight, the more visible the inclusions can be. You will need higher clarity grades for larger diamonds for them to stay eye-clean.
Inclusions and Diamond Grading
Diamond Clarity and Inclusions
The presence and nature of inclusions largely determine a diamond’s clarity grade. The fewer inclusions, the higher the clarity grade. But as mentioned above, inclusions aren’t always visible. You rarely need to choose the highest clarity grades (Flawless and Internally Flawless) to have an eye-clean diamond.
Flawless diamonds are very rare, so the highest clarity grade you’ll often see is VVS. But even a VVS clarity grade isn’t always necessary. Diamonds with a VS clarity grade have inclusions but they will often still appear clear to the naked eye. Depending on the diamond shape and the remaining 4Cs, an S1 or VS diamond can still provide a brilliant, clear diamond.
Inclusions and Diamond Cut
Different diamond cuts, and diamond shapes, can affect the appearance and visibility of inclusions.
Brilliant cut diamonds have 57-58 facets which are either triangle or kite-shaped. This makes inclusions harder to spot. The high number of facets makes the light bounce around in a way that creates a visual pattern that conceals inclusions. With diamond shapes that have brilliant cuts, such as Round Brilliant and Oval diamonds, you can often find eye-clean diamonds for a lower clarity grade.
Step cut diamonds, such as Emerald and Asscher cut diamonds, have fewer and larger parallel-shaped facets. This makes inclusions more visible because of the less dynamic way light bounces off of them. When buying a step cut diamond, prioritize clarity over the other 4Cs.
Other diamond shapes, like Radiant cut and Princess cut diamonds, have faceting structures that will help conceal inclusions.
Diamond Inclusions to Avoid
While all diamonds have inclusions, certain inclusions should be avoided when buying a diamond. The main thing you want to avoid is an inclusion that breaches the surface of a diamond. These can cause structural deficiencies and can lead to the diamond cleaving or breaking if hit at the right angle.
Lab-grown diamonds grown through the HPHT process can have metallic inclusions which causes them to be slightly magnetic. These types of inclusions don’t occur in mined diamonds or in CVD created lab-grown diamonds.
Other inclusion types are more prominent which means you may want to avoid them if they are located in a highly visible area of the diamond. “If you're sensitive about inclusions, you want to avoid inclusions that are smack-dab in the middle of the diamond as those are much more likely to be visible to the naked eye,” warns Taylor.