Everything you need to know about diamond inclusions

Choosing an engagement ring is a crucial part of any relationship because the engagement ring holds great significance and can be passed down for generations to come. During the selection process, one aspect that is considered is the center stone, typically diamonds, which are known as "a girl's best friend," representing timeless love and commitment, regardless of their cut. Diamonds have been the most popular choice for engagement rings for years, prized for their timeless appeal, brilliance, and durability.

Understanding the 4Cs is important, but equally important is understanding how diamonds are graded. Typically, diamonds come with a grading certificate detailing the cut, color, and clarity, in addition to other details such as proportions and fluorescence. Although they can be small, diamonds have a lot going on under the surface. Special tools and high magnification are required to grade diamonds, and especially to discern the clarity. Diamond clarity is ultimately determined based on the inclusions that are visible in the stone and at what magnification they are visible. Because diamonds are formed deep within the earth, different elements can become trapped within the diamond, forming imperfections within the stone that are referred to as inclusions.

Diamond Clarity Grades

Let’s first review diamond clarity grades before discussing inclusions in depth. Diamond clarity is one of the four Cs (cut, color, clarity, and carat weight) used to evaluate a diamond's quality. While there are a multitude of diamond grading labs available now, the majority use some variation of the standardized version, which was developed by The Gemological Institute of America (GIA). The scale is as follows:

  • Flawless (FL) and Internally Flawless (IF): Diamonds with no internal or external inclusions visible under 10x magnification.
  • Very, Very Slightly Included (VVS1/VVS2): Diamonds with small inclusions that are extremely difficult to detect under 10x magnification.
  • Very Slightly Included (VS1/VS2): Diamonds with minor inclusions that are difficult to see under 10x magnification but may be visible to a trained gemologist.
  • Slightly Included (SI1/SI2): Diamonds with noticeable inclusions that are easily visible under 10x magnification and may be visible to the naked eye.
  • Included (I1/I2/I3): Diamonds with obvious inclusions that are visible to the naked eye and may affect the diamond's transparency and brilliance.

As this scale indicates, diamond clarity grade and inclusions are directly linked. The diamond is assigned a clarity grade based on the existence, size, quantity, and visibility of inclusions. The larger an inclusion is, or an increased number of inclusions, will decrease the clarity grade assigned to the diamond. The location of the inclusion can also decrease the clarity grade. For example, if an inclusion is located near the edge of a diamond and can be covered with a prong, it would receive a higher clarity grade than a diamond with an inclusion located in the center of the stone, which would be nearly impossible to hide. The type of inclusion, which we will cover in more detail later, can also affect the clarity grade. Certain types of inclusions are less noticeable or more clear than others, so would not affect the grade as much as darker or more visible inclusions.

There are many different types of diamond inclusions–and not all are bad! Some are harmless, but others can affect the durability of the diamond, so it’s important to understand the differences between them.


Types of Diamond Inclusions

  • Crystal Inclusions: Crystal inclusions are other crystals trapped inside a diamond during its formation. These inclusions can vary in size, shape, and color. These can appear in many forms, such as -
  • Spots and Clouds: Small, scattered crystals or cloud-like formations within the diamond.
  • Needles: Long, thin crystal inclusions resembling needles.
  • Mineral Crystals: Crystals of other minerals with distinct shapes and colors.
  • Pinpoint Inclusions: Pinpoint inclusions are tiny spots within a diamond. They are typically small mineral crystals or gas bubbles. It’s important to note that these can affect the brilliance of the diamond.
  • Feather Inclusions: Feather inclusions are fractures that look like feathers. They can affect a diamond's durability.
  • Knots: Knots are crystals that reach to the surface of the diamond and can look like a bump on the stone. Not only will a knot affect the clarity of the diamond, but can also cause the diamond to be easily damaged if the stone is hit near the inclusion.
  • Cavities: Cavities are open spaces within a diamond that are caused by trapped gas within the stone during formation. If a cavity is large enough, it can affect the durability of the stone.
  • Cleavage: Cleavage appears as a flat, reflective surface and can affect the structure of the diamond, making it more prone to cracking.
  • Bearding: Bearding is a group of hair-like fractures on the girdle of the diamond and are usually caused during cutting or polishing of the stone.


Diamonds with higher clarity grades are rare and valuable. By comparison, diamonds with lower clarity grades, with more visible inclusions, are less valuable. Inclusions can affect the transparency and fire of a diamond because the absence of inclusions allows more light to travel uninterrupted through the diamond and back to your eye.


Why not all inclusions are bad

Although the thought of inclusions in your diamond can be viewed as a scary concept, they do have some pros. The inclusions present in your specific diamond will not be identical to any other diamond, so it serves as a way to identify yours from a group of others. These will be shown in detail on any diamond grading report and can be useful so you feel comfortable that you have the same diamond before and after work is done on your jewelry. These inclusions can also be things to note when passing down your diamond to the next generation–a way for future wearers to know and feel connected to the stone and its past. If the inclusions are not causing any durability problems with the stone, they can be seen as beauty marks, making it a one-of-a-kind diamond. They can also reduce the cost of the stone, allowing you to put more of your budget towards your ring design.

Salt and pepper diamonds


Interestingly, there are actually people who look for a diamond with lots of inclusions, which is sometimes referred to as a salt and pepper diamond. It has many black and white inclusions that give the diamond a look of having salt and pepper inside it. These diamonds are becoming very popular within the past few years with people looking for a more modern ring style. Not only are they unique looking, but they are also fairly affordable, given their inclusions.



When shopping for your diamond, it’s important to ask the right questions. Any reputable jeweler should have certified diamonds and will be able to walk you through the characteristics of the stones you are interested in. A few questions you may want to ask include:

  1. How do the inclusions affect the clarity, brilliance, and value of the diamond?
  2. Do the inclusions create a durability issue?
  3. Can you show me the inclusions on the grading certificate and under magnification?
  4. Will this diamond require unusual maintenance because of the inclusions?


Diamond inclusions are natural flaws that affect how clear, valuable, and beautiful a diamond appears. It's important to understand the different types of flaws in order to judge a diamond's quality and worth accurately. Gemologists use fancy tools to spot and study these flaws, which are crucial for grading how clear a diamond is. Inclusions like feathers, cracks, cleavage, knots, crystals, cavities, and surface scratches all affect how strong and durable a diamond is. When buying a diamond, it's important to know what flaws it has and how they might affect it over time.

Finally, remember that taking good care of your diamond is also crucial to avoid any damage, especially if it has noticeable flaws.