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What Are Inclusions in Diamonds: Clarity Characteristics Explained

Diamond with small inclusions and blemishes in it.
Inclusions in diamonds are internal or external imperfections or flaws that affect the gem's clarity. These may include tiny crystals, feathers, or other minerals trapped during the diamond's formation. Clarity grades, determined by the number, size, and visibility of these inclusions, range from "Flawless" (no inclusions visible under 10x magnification) to various levels of inclusion visibility.

Inclusions in diamonds are tiny imperfections found within the stones that occurred naturally during the diamond's formation process deep within the Earth. These inclusions can be made up of various materials such as other minerals, gases, or liquids that became trapped as the diamond crystal grew. They are like fingerprints, unique to each stone, and can affect the overall clarity of the diamond. The clarity of a diamond is a measure of how clean or clear the stone is from these natural characteristics; it's one of the key factors that can impact a diamond's value and beauty.

Understanding inclusions is important when assessing diamond quality because they influence not only the appearance but also the durability of the stone. Not all inclusions are detrimental, however; some can contribute to the uniqueness and character of a diamond. Depending on their size, number, position, and color, inclusions might be visible to the naked eye or may require magnification to be seen.

When you're considering a diamond purchase, the clarity grade provided by gemological laboratories can guide you. High-clarity diamonds have few or no inclusions visible, whereas lower clarity grades have inclusions that may be easily seen under magnification or with the unaided eye. Regardless of the clarity grade, each diamond tells a story of its billion-year journey from the depths of the Earth to you.

Understanding Diamond Clarity

A chart showing inclusions present in diamonds

When you select a diamond, understanding its clarity is crucial to gauging its quality and value. Clarity refers to the absence of inclusions and blemishes, which are internal and external imperfections, respectively.

Clarity Scale

The Clarity Scale classifies diamonds from Flawless (no inclusions or blemishes visible under 10x magnification) to Included 3 (I3) (inclusions are obvious under magnification and may affect transparency and brilliance). This scale is:

  1. Flawless (FL)
  2. Internally Flawless (IF)
  3. Very, Very Slightly Included (VVS1 and VVS2)
  4. Very Slightly Included (VS1 and VS2)
  5. Slightly Included (SI1 and SI2)
  6. Included (I1, I2, and I3)

Clarity Grade

Your diamond's Clarity Grade is determined by its position on the Clarity Scale. A grade is assigned based on the size, number, position, nature, and color of clarity characteristics visible under 10x magnification.

  • Flawless (FL): No inclusions or blemishes.
  • Internally Flawless (IF): No inclusions and only insignificant blemishes.
  • Very, Very Slightly Included (VVS): Minute inclusions that are difficult for a skilled grader to see.
  • Very Slightly Included (VS): Minor inclusions observed with effort.
  • Slightly Included (SI): Noticeable inclusions that are easy to see under 10x magnification.
  • Included (I1, I2, I3): Obvious inclusions which may affect transparency and brilliance.

Common Clarity Terms

To communicate about Diamond Clarity effectively, become familiar with these terms:

  • Inclusions: Internal characteristics such as crystals, feathers, or clouds.
  • Blemishes: Surface imperfections like scratches or nicks.
  • Eye-Clean: Diamonds that have no inclusions visible to the naked eye.
  • Magnification: The standard 10x magnification used to grade clarity.

Types of Inclusions in Diamonds



Inclusions in diamonds are natural characteristics that occur during their formation. Understanding these can help you recognize the unique history each diamond carries within.

Crystal Inclusions

Crystal inclusions are actual minerals that have been trapped inside the diamond as it formed. These could be tiny diamonds or other minerals like garnet, olivine, or chrome diopside, reflecting a glimpse into the diamond's geological environment. These inclusions can sometimes be seen with the naked eye and often enhance a diamond's unique character.

Feather Inclusions

A feather inclusion is a crack within the diamond that appears feathery when viewed under magnification. These features can vary in size and are often white or transparent. While some feathers are harmless, others can affect the diamond's durability if they reach the surface or are particularly large.

Cloud Inclusions

Cloud inclusions consist of clusters of pinpoint inclusions too small to discern individually. They appear as hazy areas, hence the name "cloud," and can affect the stone's clarity and transparency. The density of these inclusions can impact how noticeable they are and their effect on the diamond's brilliance.

Cavity Inclusions

Cavities are small hollow areas within the diamond, typically resulting from a crystal inclusion falling out or being forced out during the polishing process. The appearance of a cavity can vary depending on the size and where it's located within the diamond.

Knot Inclusions

Knot inclusions occur when a diamond crystal reaches the surface during the cutting process. Visibly, they can sometimes appear as a raised area on a facet of the diamond, and they can affect both the surface texture and the overall clarity.

Indented Natural Inclusions

Indented naturals are parts of the original rough diamond's surface that are left on or extend into a polished stone. These inclusions are typically found around the girdle area and are deliberately left to retain more carat weight. Their visibility varies depending on how far into the diamond the natural extends.

Identifying Inclusions

A gemologist finding inclusions in diamond.

Inclusions are internal characteristics found within diamonds, often affecting their clarity and value. Precise identification of inclusions is crucial for grading and valuation purposes.

Using Magnification

With magnification tools, you can observe inclusions that are not visible to the naked eye. A jeweler's loupe, typically at 10x magnification, is standard for inspecting inclusions. High-powered microscopes can provide more detailed images, revealing the size, shape, and position of these internal features.

Gemologist Inspection

A professional gemologist uses specialized equipment and their expertise to determine the nature of inclusions. They assess whether inclusions are crystals, feathers, or clouds, which can influence both the appearance and integrity of the diamond. A gemologist's inspection can also offer insights into the diamond's formation conditions.

Grading Reports

Grading reports, issued by reputable gemological laboratories, document the characteristics of a diamond, including its inclusions. These reports provide a mapped diagram showing the inclusion types and locations. Grading reports serve as an essential reference for buyers and sellers in the diamond industry, certifying the quality of the gemstone.

Impact of Inclusions on Diamond Value

A woman buying a high quality Engagement Ring

Inclusions in diamonds play a crucial role in determining their value. As the most sought-after gemstone, the four C's—carat weight, color, clarity, and cut—dictate a diamond's worth, with inclusions affecting both clarity and color.

Influence on Clarity and Color

Inclusions can significantly affect a diamond's clarity. Clarity grades are assigned based on the number, size, relief, nature, and position of these characteristics within the diamond. Inclusions can range from invisible to the naked eye to visually apparent under magnification, impacting the clarity grade and thus, the value. For instance, a diamond with fewer and smaller inclusions generally achieves a higher clarity grade, making it more valuable.

Color is another important factor. Although not all inclusions impact color, those that do can either detract from the diamond's pureness or, in rare cases, enhance its hue. However, inclusions often result in shades that lower the diamond's color grade, decreasing its value unless the color is particularly rare and desirable.

Assessing Durability Issues

Inclusions can also affect durability. While diamonds are renowned for their hardness, certain inclusions, particularly those near the surface, can weaken a diamond's structure. You might find that such diamonds are more susceptible to cracking or chipping, which poses a considerable risk for high-impact areas. Thus, diamonds with these types of inclusions may be valued lower as durability is a critical component for jewelry that’s worn daily.

Visibility and Eye-Clean Standard

The term "eye-clean" refers to diamonds where inclusions are not visible to the naked eye when viewed from approximately 6-12 inches away. This measure is vital when determining value, as eye-clean diamonds are in high demand.

An eye-clean diamond may not necessarily be the highest clarity grade but will be free of visible inclusions, making it a balance of value and beauty. These diamonds offer the best trade-off, as they don't carry the premium of flawless stones, yet still appear perfect to the viewer. Visibility of inclusions thus directly influences a diamond's desirability and market value.

Treatment and Enhancement

A close up view of heat treated diamond.

In the realm of gemology, treatment and enhancement techniques are employed to improve the appearance of diamonds, often by addressing their natural inclusions. These methods do not significantly change the intrinsic properties of the diamonds but instead enhance their visual appeal.

Laser Drilling and Filling

Laser drilling is a treatment process in which a laser creates a minute channel within a diamond to reach and either remove or significantly reduce the visibility of inclusions. Post-drilling, these channels may be filled with a substance to diminish the visibility of the fracture. This filling material typically has similar optical properties to the diamond, making the treatment less noticeable.

Enhancement Processes

Enhancements can also include heat and pressure treatments, often used to transform the color or clarity. Heat can cause permanent alterations in the diamond, sometimes improving color or altering inclusions. High-pressure, high-temperature (HPHT) treatments can alter the crystal structure and appearance of the stone, for example, to transform certain brown diamonds into colorless diamonds or enhance yellow and orange hues.

Disclosure and Ethics

Moreover, the ethics of disclosure come into play; it's imperative that any treatments or enhancements made to a diamond are fully disclosed to potential buyers. This transparency maintains the integrity of the diamond market and ensures that consumers are making informed decisions about their purchases.

Natural vs. Lab-Grown Diamonds

Natural vs Synthetic diamond
Aspect Natural Diamonds Lab-Grown Diamonds
Origin Formed naturally deep within the Earth's mantle over millions of years through geological processes. Created in a controlled laboratory environment using advanced technological processes.
Environmental Impact Mining natural diamonds can have environmental consequences, including habitat disruption and carbon emissions. Significantly lower environmental impact as the production process is more controlled and uses fewer resources.
Ethical Considerations Issues such as conflict diamonds (blood diamonds) have raised ethical concerns in the diamond industry. Conflict-free and ethically sourced, providing a transparent and ethical alternative.
Cost Can be more expensive due to the rarity and natural formation process. Often more affordable as the production process is controlled, leading to cost savings.
Quality Varies in quality, and inclusions are a natural part of the formation process. Can have fewer inclusions and consistent quality due to controlled growth conditions.
Customization Limited customization options as the natural formation process determines the diamond's characteristics. Highly customizable, allowing buyers to choose specific size, shape, and color preferences.
Availability of Rare Colors Natural diamonds come in a range of colors, and rare colors are highly valued. Can be produced in rare colors that may be challenging to find in natural diamonds.
Transparency May lack transparency in terms of origin and ethical sourcing. Comes with detailed documentation, ensuring transparency about origin and characteristics.
Technological Innovation Traditional diamond industry has been slow to adopt technological advancements. Fosters innovation in the diamond industry with advanced technological processes.
Symbolism Traditionally associated with rarity, love, and endurance. Increasing acceptance as a symbol of love, with emphasis on ethical and environmental considerations.

In the debate between natural diamonds and lab-grown diamonds, one of the central points of comparison is the presence and nature of inclusions. Understanding the formation process and the characteristics of inclusions is fundamental to appreciating the differences.

Formation Process

Natural Diamonds form over billions of years under high-pressure and high-temperature conditions deep within the Earth’s mantle. They make their way to the surface via volcanic eruptions, often included in a type of rock called kimberlite. The conditions under which these diamonds form lead to unique and intricate inclusions, the fingerprints of a natural diamond's personality.

On the other hand, Lab-Grown Diamonds are created in controlled laboratory environments using two main methods: High Pressure-High Temperature (HPHT) and Chemical Vapor Deposition (CVD). These man-made processes can mirror natural conditions and typically occur over weeks or months, leading to quicker crystallization with fewer, if any, inclusions.

Inclusion Characteristics

Inclusions in natural diamonds typically consist of other minerals or fractures that occur while the diamond is formed or transported to the surface. These natural inclusions can be as varied as the earth's geology itself, making each natural diamond unique.

Conversely, lab-grown diamonds may have inclusions resulting from the growth process, such as metallic flux in HPHT diamonds or non-diamond carbon in CVD diamonds. These inclusions differ from natural ones, being indicative of their man-made origin. Even though lab-grown diamonds can have inclusions, they are generally fewer and different in type due to the controlled conditions in which they are made.

Both types of diamonds may have aesthetic and structural variations dictated by their inclusions. Whether you're attracted to the singular history of natural diamond inclusions or the modern marvel of lab-grown diamonds, it's these characteristics that contribute to the stone's unique beauty and story.

Buying Tips for Diamonds with Inclusions

High Quality Moissanite Engagement Rings for sale

When searching for diamonds, understanding how inclusions affect the stone's clarity can guide you in selecting a piece that balances beauty with budget.

Choosing the Right Clarity Grade

Inclusions are imperfections found within a diamond, and they play a significant role in determining the clarity grade of the stone. Your goal should be to select a grade that fits your preferences and budget. For instance, a diamond with a VS (Very Slight) clarity grade will have inclusions that are not visible to the naked eye but will be more affordable than a flawless diamond.

Analyzing Inclusion Placement

The placement of inclusions can impact a diamond's appearance significantly. Look for diamonds where inclusions are located near the edges or are hidden beneath the setting, as these can be less noticeable. A strategically placed inclusion can result in a more attractive diamond that doesn’t compromise on brilliance.

Optimizing for Budget and Beauty

Your budget need not restrict you from acquiring a beautiful diamond. Opt for lower color or cut grades to allocate more of your budget to a better clarity grade if inclusions concern you. Conversely, if slight inclusions don't bother you, you might prioritize a higher cut grade for better sparkle, after considering the inclusion's visibility. Remember, inclusions affect each diamond uniquely, so choose the one that appeals to your eye and aligns with your financial plan.

Frequently Asked Questions

Inclusions in a diamond are natural characteristics and can affect both its clarity and value. Understanding them can help you make informed decisions about purchasing and caring for your diamond jewelry.

How can you identify inclusions in a diamond?

You can identify inclusions in a diamond by using a jewelers' loupe, which magnifies the gemstone up to 10 times, allowing you to see internal and surface characteristics.

What impact do inclusions have on a diamond's clarity?

Inclusions can impact a diamond’s clarity by causing blemishes or internal characteristics that are visible under magnification. These can affect the overall appearance and brilliance of the diamond.

Which types of diamond inclusions are considered most desirable?

Feather inclusions, which are small cracks inside the diamond, can sometimes be considered desirable if they do not threaten the diamond's structure and are not overly noticeable.

Are there specific inclusions that should be avoided in diamond jewelry?

Avoid inclusions such as large feathers or clouds that significantly affect the transparency and internal structure, as they can diminish the diamond's brilliance and durability.

Is it possible to remove inclusions from a diamond without affecting its integrity?

It is possible to treat certain inclusions through processes like laser drilling or fracture filling, but these can affect the diamond's value and may require disclosure.

What are the differences between black inclusions and other types of inclusions in diamonds?

Black inclusions are usually minute minerals or graphite inside the diamond and are more visible than other inclusions, potentially impacting the stone's aesthetic and clarity more significantly.

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