You are most like aware of diamond clarity – one of the four major criteria that determine a stone’s quality. You also know that clarity is graded by the number and visibility of the flaws. But have you ever thought about how diamond flaws develop and why they can be useful?
What are Diamond Inclusions?
Diamond inclusions are flaws that develop within a stone at the time it was formed. There are different types of inclusions, the ones that may be visible to the naked eye and others that are visible only under magnification.
The imperfections that are inside the stone have a natural origin and are called internal flaws. In most cases, natural flaws can not be fixed and that’s perfectly normal.
The flaws that appear on a diamond’s surface are called external flaws or blemishes. Depending on nature, these flaws can be easily fixed.

How do Diamond Inclusions Appear?
Natural diamonds are formed under high pressure and extreme heat deep inside the earth. During this process, other crystals can be captured inside the diamond’s structure.
These crystals may look like small dots or light and dark clouds if there are a lot of dots in a certain area within the stone.
Natural diamonds do not form smoothly. There are a lot of irregularities within the crystalline structure. Such type of flaws looks like small lines.
During the formation, a diamond may also capture air within its crystals and it will be seen as bubbles. Another type is cracks, they may develop naturally and be visible to the naked eye.
Can Diamond Flaws Develop After Purchase?
Diamond inclusions are permanent and they do not appear or disappear suddenly. There is no way a new inclusion can occur within your stone.
For example, if you notice a black dot or cloud within your stone, and you think it’s new, you are probably wrong. This effect may occur when dirt particles accumulate on a diamond’s surface, they block light and reduce stone’s sparkle, making existing internal flaws more visible.
In terms of cracks, this may be true, but cracks do not look like small inclusions.
You may notice chips and other flaws on the surface of your diamond that may develop over time, but these flaws are not internal and they are not considered inclusions.

Why Diamond Flaws Can Be Useful
Yes, diamond inclusions can be useful in some cases and there is no typo.
Inclusions are unique to every single stone and they can help you to easily identify your diamond among the others.
Certified diamonds usually contain a diagram of all inclusions in their reports, this diagram is also called a “diamond plot”.
If for any reason you are in doubt that the stone is not your original diamond, you can always identify it by its unique inclusions.