Diamond clarity

Of all of the Four Cs, Clarity is the easiest to evaluate and considered the most straightforward for the average diamond consumer to understand.

While diamonds are being formed deep within the Earth’s surface, the extreme heat and pressure that help shape them can also create cracks, flaws or inclusions. These internal and external imperfections or blemishes are considered to be the natural birthmark of every diamond. Technically, a diamond’s interior irregularities are referred to as inclusions and a diamond’s exterior irregularities are referred to as blemishes. Frequently, these marks are detectable only under a powerful microscope or jeweler’s loupe, and therefore do not visibly affect the appearance or beauty of a diamond.

When a professional gemologist evaluates or grades a diamond’s clarity, typically these inclusions and blemishes are mapped to create a “fingerprint” of the diamond. This “fingerprint” is what distinguishes the diamond as unique.

What Are Inclusions?

The internal irregularities in a diamond are the diamonds’ inclusions. Inclusions typically consist of crystals, clouds and feathers. Crystals are tiny minerals that become trapped inside a diamond during its formation. Clouds are foggy spots in the diamond which are created by crystals that are so small that they can only be seen under a 10x magnifying microscope. Feathers are fractures in a stone that, when relatively small, are inconsequential to the strength of a diamond. Large feathers, however, can weaken a diamond’s structure, and will decrease the value and quality of your diamond.

What Are Blemishes?

Blemishes are external impurities or marks on the surface of a diamond, and typically appear as a scratch imperceptible to the naked eye. Blemishes typically have less impact on a diamond’s value, beauty and grade since they rarely affect the strength and structure of the diamond.

Diamond clarity grading scale

The size, color, and dimensional orientation of imperfections and blemishes determines how visible they are to the naked eye. The grade of the clarity is assigned to each diamond based on appearance under 10x magnification.

Imperfections obstruct light refraction, making diamonds less brilliant. The larger the imperfections, the worse the diamond’s ability to reflect the light, degrading the quality of the gemstone.

The Gemological Institute of America’s (GIA) International Diamond Grading System is the globally recognized standard for diamond clarity assessment.

With 11 grades, the system classifies a diamond’s clarity based on the nature, position and size of its inclusions and exclusions. The list below summarizes the GIA’s International Diamond Grading System.

Diamonds with the least amount of flaws hold the highest clarity grading. Flawless diamonds are extremely rare, considered to be the most beautiful of all diamond grades. Because they are so scarce diamond experts consider Internally Flawless diamonds (IF) to be the most valuable examples of near-perfection in the international diamond market.

Trained gemologists grade the clarity of a diamond by examining it top-down with the use of a 10x magnifying microscope and looking at the diamond from the top down. The position, size and type of inclusions and blemishes are all crucial factors in evaluating the clarity of a diamond. Imperfections located on or beneath the table of the diamond are easier to detect and affect clarity grade more than those located around the sides of the diamond. Larger marks, darker marks, and deep marks will also significantly affect the clarity of the diamond.   

  • FL, IF Flawless/Internally Flawless: Flawless diamonds have no inclusions or blemishes detectable under 10x magnification, and are extremely rare. Internally flawless diamonds have no detectable inclusions under 10x magnification, are rare and very valuable.
  • VVS1/VVS2 Very Very Slightly Included: Inclusions and blemishes are extremely difficult for a skilled grader to detect under 10 x magnification.  
  • VS1/VS2 Very Slightly Included: Inclusions and blemishes are detectable under 10x magnification, however they are minor flaws that do not impact the diamond’s beauty and are frequently invisible to the naked eye.
  • SI1/SI2 Slightly Included: Inclusions and blemishes are easily noticeable under 10x magnification and may also be visible to the naked eye.
  • I1,I2,I3 Included: Inclusions and blemishes are obvious under 10x magnification and typically visible to the naked eye. These flaws may negatively impact the transparency and or brilliance of the diamond.

Other diamond clarity grading scales

In 1992 the European Gem Laboratory (EGL) introduced another grade of clarity: SI3. Ostensibly, many industry craftsmen complained there was too wide a gap between the GIA standard grades SI2 (slightly included) and the I1 (included). Hence, why not offer a SI3 grade to bridge the gap? GIA did not recognize this new grade and a lot of jewelers believed it was just a veiled attempt to price gouge the most gullible consumers by selling them I1 grade diamonds at SI2 prices.

Different diamond grading labs and agencies developed their own color and clarity systems. All grading systems rely on human judgment and ability to determine the grade based on the overall agency grade description. Oftentimes the same diamond can be graded differently by the same agency if sent for grading more than once. Some agencies are considered stricter and more precise in how they grade stones. Diamonds tested by agencies such as AGS and GIA command a premium, while comparable stones graded by such agencies as EGL, HRD, and IGI are sold at 3% to 20% less.

What Clarity Grade Should I Choose?

We recommend that you work within your budget to select a diamond with the least amount of inclusions and blemishes, qualities which will negatively impact the value and durability of your diamond.

Many diamond purists insist on FL or IF diamonds, believing that these diamonds are 100% flawless, however, it is important to note that this is not the case. Almost all diamonds have some flaws. FL and IF diamonds simply have no flaws detectable under 10x magnification. SI and VS diamonds are typically considered clarity grades of fantastic value since their inclusions are minor and invisible to the unaided eye.

When looking at diamonds with many facets and a highly brilliant cut, such as round brilliants, it is typically impossible to differentiate between SI1 clarity and VS clarity or greater. For this reason, SI1 or VS2 will give you a beautiful diamond at a much lower price tag. However, before purchasing your diamond, it’;s always a good idea to check with a customer service representative to ensure that your diamond does not have any “eye-visible” inclusions.

When looking at fancy shaped diamonds that have fewer facets and larger tables, such as Emerald or Asscher diamonds, inclusions are easier to detect with the naked eye. Therefore, we recommend choosing a fancy shaped diamond with a clarity grade no lower than VS2.