Diamonds 101: What Are Diamond Inclusions?

Perfect diamonds, or diamonds without any irregularity or flaw, are rare. Most of the time, diamonds come with slight imperfections that are not usually visible to the naked eye. This precious stone consists of natural marks that are only visible under 10x magnification, and these birthmarks are called inclusions.

Inclusions determine the quality of the diamond and are what separates synthetic from natural ones. Only professional graders can evaluate the inclusions or clarity of the diamonds and base their value on the inclusions’ size, quantity, placement, tone, and color. 

If you’re planning to propose soon, you should know that not all diamonds are created equal, and knowing the types of inclusions can help you choose the perfect ring for her. We’ve rounded up the different types of inclusions in diamonds just for you.


Cavity is distinguished as a large or deep opening in the stone’s surface, mostly due to the aftermath of the polishing stage. When an internal inclusion becomes dislodged from the diamond, it creates an opening on the surface. This opening then traps dirt and oil that become darker and more visible over time.


Lines that resemble strands on the diamond’s surface are called bearding. These lines are often due to the cutting process and run from the girdle to the stone’s surface. When a girdle is heavily bearded, it gives off a grey and fuzzy fringe that looks like scratches. 


A chip is best described as a tiny, superficial opening on the surface that’s—most of the time—found near the girdle, culet, or facet junctions. Unlike other inclusions, a chip is usually caused by human intervention. Chips are damages resulting from regular wear and tear or accidents.


Cloud inclusions are a group of pinpoints or crystals that are clustered near each other. There are times when the nature of the cloud inclusion can compromise the appearance of the diamond. When the size of the cloud inclusion gets out of hand, it can cause the diamond to look hazy, which can have an adverse effect on light transmission. However, small and diffused clouds are generally fine.


To put it simply, a crystal inclusion is a mineral crystal found within the diamond. The color of the crystals varies, from reddish garnets and black carbon to greenish peridots and colorless. Colorless crystals are a product of another diamond embedded within that particular diamond. Colored crystals are classified under the more obvious inclusions, so this may affect the quality and desirability of the diamond.


This type of inclusion is a speck of crack or fracture within the stone, and can either be transparent or look white and feathery. The durability of diamonds can be compromised with severe feathers, especially when these inclusions reach the surface or in close proximity with the girdle. Also watch out for an unattractive coloration of the feather, which is an indicator that the diamond may not be too durable. 


Internal graining is a product of irregular crystal growth and may look milky or hazy. They can appear as faint lines or streaks, or even creases and reflections.

Indented Natural

Before a diamond is polished, it is first a rough mineral. An indented natural is an area on the rough surface that dips below the polished part of the diamond. An indented natural can be considered as a leftover of the polishing process, commonly found at the girdle. 


This crystal can be either white or transparent that can be found on the polished surface. A knot can mimic raised areas on a facet surface or group of facets.


A needle inclusion is one that’s hard to notice since it’s only visible under 10x magnification. Its long, thin needle shape is normally white or transparent. The diamond’s clarity may be compromised if the needle inclusion appears in clusters.


Just like a needle inclusion, pinpoints are not visible to the naked eye. You need to view it under 10x magnification to see the minuscule white or black crystals embedded within the diamond. 

Twinning Wisps

This type of inclusion is a combination of different inclusions. Pinpoints, clouds, crystals, and feathers that arise during the formation process are what consist twinning wisps. Due to unfavorable conditions, a diamond may stop growing, and this is when twinning wisps are formed. Twinning wisps appear when the diamond regrows in a different direction, which can sometimes take as long as thousands of years after. 

Diamond Clarity

Diamonds are beautiful, no matter the type of inclusion it has. However, inclusions affect the clarity grade of the precious stone, so it’s crucial that you’re aware of its different types. 

Feel free to reach out to us here at Lily & Co so we can assist you in finding the perfect diamond ring for your other half! 

Images from: Teacher and Your Diamond Guru