Diamond Clarity
Every natural diamond is formed under immense heat and pressure, and during this process, tiny imperfections—known as inclusions and blemishes—develop within or on the stone
While these characteristics are a natural part of a diamond’s structure, their size, location, and visibility can impact both how a diamond looks and how light moves throughout it.
Diamond clarity is the measurement of these natural imperfections, assessing how noticeable they are and their effect on the diamond’s overall appearance.
In this article, we’ll go over the fundamentals of diamond clarity, including how it’s graded and what to consider when making a selection.
Whether you’re looking for a flawless diamond or one that has the perfect balance between beauty and value, understanding clarity will help you make a confident and informed choice.
How Inclusions and Blemishes Affect Clarity
Not all inclusions and blemishes are equal. Their size, location, and concentration affect how much they impact a diamond’s overall appearance.
- Size – Inclusions vary widely by size. Some can be seen with the naked eye, while others need magnification. Some are so big that they can even interfere with light reflections within a stone.
- Location – Inclusions near the center of the diamond (directly beneath the table) are more visible and can interfere with light performance. Those near the edges or girdle may be less noticeable and can sometimes be hidden by prongs in a setting.
- Grouping – When inclusions are grouped together, they can create a hazy or cloudy effect, reducing transparency. A single small inclusion may have little impact, but multiple inclusions in one area can significantly affect clarity.
Blemishes occur on the exterior of the diamond and can be caused by natural formation or the cutting and polishing process. Common blemishes include scratches, pits, and nicks.
- Impact on Clarity – Minor blemishes often have less of an effect on clarity compared to deep internal inclusions. However, excessive surface marks can still reduce overall brilliance, especially in step-cut diamonds like emerald or Asscher cuts. In these shapes, the large front-facing facets can make blemishes more noticeable.
How Diamond Clarity is Graded
To standardize clarity assessment, the Gemological Institute of America (GIA) developed a six-category, eleven-grade scale that evaluates a diamond’s overall clarity based on a 10x magnification:
- Flawless (FL) – No inclusions or blemishes visible under 10× magnification. Super rare.
- Internally Flawless (IF) – No inclusions, but minor surface blemishes visible under 10× magnification.
- Very, Very Slightly Included (VVS1 & VVS2) – Minuscule inclusions that are difficult for even a skilled grader to detect under magnification.
- Very Slightly Included (VS1 & VS2) – Small inclusions that are minor and range from difficult to somewhat easy to see under magnification.
- Slightly Included (SI1 & SI2) – Noticeable inclusions under magnification, though many SI1 diamonds remain eye-clean.
- Included (I1, I2, & I3) – Inclusions that are obvious and may affect transparency, brilliance, and structural integrity.
While flawless diamonds are the rarest, most diamonds used in fine jewelry fall within the VS (very slightly included) or the SI (slightly included) range; it’s here where inclusions are minimal and often undetectable to the naked eye.
Choosing a Diamond Based on Clarity
Unlike cut or color, clarity is oftentimes less noticeable to the untrained eye.
Many diamonds in the VS (Very Slightly Included) and SI (Slightly Included) ranges appear “eye-clean”, which means their inclusions are too small to detect without magnification.
Because of this, clarity is one of the most flexible areas where buyers can adjust their preferences to prioritize other factors—such as carat weight or cut—without compromising on beauty. Here are a few examples:
- Clarity vs. Color: Depending on the location and the size of the inclusions, in most cases diamond color has a more immediate impact on appearance than clarity. A diamond with minor inclusions but exceptional color may appear more visually striking than one with higher clarity but a noticeable yellow hue.
- Clarity vs. Cut: Cut has a far greater impact on a diamond’s beauty than clarity. A well-cut diamond with a slightly lower clarity grade will often look more brilliant than a flawless diamond with a poor cut.
- Clarity vs. Carat: If size is a priority, opting for a slightly lower clarity grade can allow for a larger stone within the same budget.
Note also that Clarity becomes more critical depending on the diamond’s shape.
Brilliant-cut diamonds (like the round, oval, or cushion shapes) are more forgiving because their faceting patterns refract light intensely and help mask inclusions. In contrast, step-cut diamonds (like the emerald or Asscher cuts) have large, open facets that make inclusions more noticeable.
As a result, it’s recommended that step-cut diamonds have higher clarity grades to ensure an optimal appearance.
Conclusion:
Diamond clarity plays an important role in determining a stone’s overall appearance and value, but it’s just one piece of the puzzle when selecting the right diamond for you.
While higher clarity grades indicate fewer inclusions, many diamonds in the VS and SI range can offer a stunning look without the premium price of Flawless or Internally Flawless stones.
Understanding how inclusions and blemishes impact light performance, visibility, and durability allows you to make a more informed decision, and allows you to make appropriate compromises against other characteristics like color and carat, where needed.
If you’re ready to explore your options, our experts at Takohl Custom Jewelry are here to help. With over three decades of experience in crafting custom diamond pieces, we have fostered close relationships with diamond dealers worldwide to help each of our clientele find quality diamonds at competitive prices.
Come visit us at our West Loop gallery and experience the world-class expertise that has made us Chicago’s premier custom jewelers for over thirty five years.