A Complete Guide to Diamond Inclusions

May 03, 2021 BY :Diamonds on call

what are diamond inclusion

If your search for ultimately perfect diamond has begun, then you must have come across the term inclusion or popularly known as impurities. If your finalized diamond has passed of perfect color and perfect cut, yet the last leap of ultimate sparkle might be a hurdle to come through. The inclusion falls in the clarity grading criteria of diamonds.


The inclusions can usually be seen under 10 x enlargements, making them unnoticeable to the naked eyes. Diamonds that have large inclusions or many inclusions are known as a low clarity grade. Understanding what inclusions mean, how are they formed, types of inclusions and many more factors will bring you a step closer to unravelling diamond purity perfection.


What are diamond inclusions?


Diamonds are formed naturally inside the earth’s surface. Almost all diamonds contain inclusion(s) in either form. Take inclusion as a ‘birthmark’ on a diamond. However, any mark on the surface of the diamond is known as a ‘blemish’.


Although inclusion might seem like a flaw, in a way, it adds uniqueness to diamonds. It is a common misconception that inclusion is the black marks seen in diamonds. The truth behind these black marks is that they are crystals inside the diamond containing mineral carbon. There are various types of inclusion in diamonds, and surprisingly, not all are formed during the natural processes. Each inclusion states a different cause resulting in a different effect on the appearance.


How do the Gemologists Grade inclusions in Diamond?


GIA and IGI are the reputed third-party diamond certifying laboratories. They follow a set of strict guidelines for determining and identifying the inclusion in Diamond. From location to size, numerous factors lay a strong impact on a diamond’s clarity grade.


Here are the notable criteria judged by Gemologists for identifying diamond inclusion:


1. The size of the inclusion is essential to determine the damage done by the inclusion. The same holds high importance in identifying the clarity grade of the diamond.


2. The quantity (numbers) of the inclusion as the more inclusions will be there on the diamond, the less it will be on the clarity grade.


3. The next important aspect is the location of the inclusion on the diamond. The inclusions on the surface are less likely to be degrading the diamond than the ones inside.


4. The impact of the inclusion(s) on the diamond matters the most. The inclusions might look small and be on the surface but could have affected the diamond substantially.


Types of inclusions


Bruise: The inclusion occurs at a facet junction and appears as if any tiny root-like feathers.



Cavity: This inclusion appears like a deep or large opening on the diamond’s surface. The inclusion is usually created while polishing the internal blemish and gets dislodged, leaving an opening on the diamond’s surface. The cavity often traps dirt and oil, which eventually increases visibility.



Chip: This inclusion is typically man-made and caused by accidental knocks or wear and tear. The chip is a small/ shallow opening on the diamond’s surface near the girdle or facet junctions.



Cleavage: Cleavage inclusions are straight cracks. In some cases, these cracks can be deeper and split the diamond apart. This inclusion is considered a serious flaw and diminishes stability.



Cloud: This type of inclusion comprises many very small pinpoints, difficult to separate individuals found tightly packed around each other. Depending upon the nature of the inclusion, it could be a severe issue when it comes to appearance.



Crystal: When a mineral crystal is contained within the diamond, it is known as crystal inclusion. The crystal could be of any type like colourless or black could be carbon, red like the garnets, or even green such as peridots.



Etch Channel: This inclusion is a hollow tunnel that starts from the surface and penetrates the body. It is very similar to internal laser-drilled inclusion but created naturally.

etch channel


Extra facet: Extra facet inclusion is a flat and polished surface created while polishing the diamond to cover the naturals. The inclusion can appear on the surface of the diamond.

extra facet


Feather: It appears like a fracture inside the diamond. Depending on the viewing angle, a feather inclusion could be transparent, or it can appear when the light catches the facture. In some cases, where feathers reach the girdle, surface, or both, it can give rise to durability issues.



Indented Natural: This inclusion is usually found at the girdle and is the rough part that lies below the polished surface of the diamond. It is a part of the unpolished diamond that was left untouched during the manufacturing process.

indented natural


Internal Graining: This occurs due to the irregularity of crystal growth. This inclusion could be in lines, curves, or angles that sometimes affect brilliance at 10X magnification.



Internal Laser Drilling: During the laser drilling in the diamond sometimes creates a surface-stretched feather or could expand a pre-existing feather that could reach the surface of the diamond. This could cause durability issues. In some cases, the inclusion is controlled by bleaching.



Knot: This inclusion in a white or transparent crystal-like appearance extended to the surface.


Laser Drill-hole: It is in the form of a tiny, surface-reaching hole caused by a laser light beam while drilling the diamond.



Manufacturing Remnant: This is a man-made inclusion that occurs during the polishing or could result from encountering excessive heat. Some cases show milky patches, but mostly manufacturing remnants are not visible.

Manufacturing Remnant


Minor Details of the polish: The minor detail of polish is barely noticeable and doesn’t count as a flaw even by the grading system. They are the tiny marks left on the surface while polishing.



Natural: A natural inclusion occurs due to the natural course. It is a rough part of the diamond kept untouched during the manufacturing process. Diamond cutters prefer to leave on the inclusion to show that they haven’t taken much diamond off during the process.



Needle: This inclusion is a thin, elongated tiny rod in the form of a crystal that is visible at 10X magnification.



Pinpoint: It looks like a tiny dot or a very tiny crystal visible under a magnifying glass.



Surface Graining: This inclusion occurs due to impurities resulting in growing thin lines like crystals on the surface of the diamond. The inclusion can cause grain lines after the crystal is removed. These lines could disappear after polishing.



Twinning Wisp: This inclusion is a series of clouds, pinpoints, or crystals formed during the growing process. The inclusion is linked with twinning planes and crystal distortion.



Read more: A Brief History of Diamond Cutting


What are the best inclusions to have in a diamond?


Inclusions in the diamond are flaws. However, if the diamond inclusion is microscopic or slightly included, then the same could be overlooked. This draws a question – what types of inclusions are negligible.


Inclusions like pinpoints, needle, and feathers can be considered negligible inclusions or the best inclusions to have in a diamond. The only factor that must be complied with these inclusions is that they should only appear at 10x magnification and not above the same. We recommend these inclusions because they are primarily white or colourless and very difficult to see with the naked eye.


Apart from the inclusions mentioned above, few inclusions should be avoided entirely: cavity, chip, natural, indented natural, knot, and etch channel.


How to choose a diamond with inclusions?


Diamonds in the industry are judged entirely on their purity graded by the laboratory. The diamonds go through wear and tear for ages to reach an actual shape. Statistically, only 2-3% of all diamonds are of the purest quality. This draws us to the conclusion that most diamonds have inclusion.


When a diamond has inclusion, then the value automatically weighs down. Despite that, the diamonds with the least flaws are the most unique and hold high value. Then, how to determine the best diamond. We will start with an example.


How to choose a diamond with inclusions


Both the figures have diamonds with inclusion. They both have equal carat, colour grade, clarity grade, and cut, yet the diamond in fig 1 is more valuable than fig 2. The reason is quite visible; the inclusion in fig 2 diamond is at the centre and visible, whereas, in fig 1, the inclusion lies on the side and thus negligible.


The GIA or any trusted gemmologist report states the inclusion but not its density. Therefore, a thorough look before buying is essential.


Why choose Diamonds On Call that help you choose the correct diamond?


Inclusions in diamonds can cost immeasurably. All this brings to a simple question - How to identify and make a perfect purchase? Well, the answer to this question is purchasing through diamonds on call. This is a B2B platform where diamonds are verified at multiple stages. In case of inclusions, Diamonds On Call quality grades every diamond before shipping it to the customer. Diamonds On call verifies certificate, checks for damages, and matches every aspect of the diamonds, including brown-green milky and eye-clean.


You can also read: What Makes Diamonds So Expensive?

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Diamonds on call Team

Diamonds on call is building an online platform, where diamond (certified or parcel) buying experience becomes smooth and easy for jewelers around the world. Our team works 24x7 to make sure the customer buying experience is fantastic.

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