Diamond Clarity Scale: Assessing the GIA Chart

Sharif Khan
Sharif Khan
Last Updated    EST 
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The presence or absence of inclusions or blemishes determines a diamond's clarity grade – these are essentially birthmarks resulting from the diamond's extended formation process. Each diamond has distinct clarity characteristics, contributing to its uniqueness and value.

The Gemological Institute of America (GIA) grades diamond clarity on a scale ranging from FL (Flawless) to I3 (Included 3), with FL representing the highest clarity and I3 indicating the lowest.

Personal preference and budget constraints play a key role when buyers determine the right clarity grade for their needs. Interestingly, inclusions not only aid in identifying a diamond but also lead some individuals to favor Very, Very Slightly Included (VVS) diamonds over completely flawless ones.

Insights to Appreciate

  • Imfections or inclusions are natural birthmarks of diamonds, giving each diamond a unique identity. 
  • An inclusion's type, size, and location make a big difference when evaluating a diamond for quality.
  • If correctly understood, factors related to diamond clarity offer the most flexibility when prioritizing the 4Cs.

Clarity Insights to Consider

  • Diamonds in the flawless to VVS range are considered investment grade. However, they must also have exceptional color, cut, and weigh above 1 carat. 
  • VS1 and VS2 are also high quality clarity grades, especially if matched by equally good color and cut grades. 
  • SI1 and SI2 are great options for budget shoppers; however, in the above 1.5 carat diamonds, SI2 clarity must be closely evaluated.

Read our article on how to prioritize the 4Cs for more insights.

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Diamond Clarity Highlights

Key Factors The quantity of natural imperfections present in a diamond determines its clarity grade. A diamond's clarity is determined by two key factors: blemishes, external flaws like chips and scratches, and inclusions, which refer to internal defects such as crystals and feathers. Further details on clarity categories are provided below.
Flexible C Assessing the clarity of a diamond is a highly technical process. When effectively managed, it becomes one of the most adaptable aspects among the 4Cs, allowing for compromises while prioritizing diamond quality. Consequently, understanding which types of inclusions are more desirable and which ones to avoid is paramount.
Type & Location The location of an inclusion within the diamond also holds significance. Inclusions at the diamond's center and on the table are generally considered unfavorable, mainly if they manifest as sizable black crystals. Conversely, suppose these inclusions are positioned near the girdle's side and are represented by white feathers or pinpoints. In that case, they are often preferred, provided they do not weaken the girdle, rendering it susceptible to chipping.

Diamond Clarity Chart

A diamond's capacity to radiate brilliance is partly derived from its flawless nature, which permits light rays to traverse through, resulting in vibrant colors and captivating sparkle patterns. The consistency, properties, and presence or absence of inclusions substantially influence a diamond's clarity grade.

Since diamonds undergo an extensive natural formation process, most exhibit surface birthmarks leading to blemishes or internal birthmarks known as inclusions. Inclusions encompass a variety of forms, including cloudy or pinpoint inclusions, cavities, and cleavages. Additionally, blemishes such as nicks, pits, and fractures appear in diverse configurations. Almost all diamonds possess clarity imperfections due to their millions of years of formation. Inclusions can also arise from the intensive cutting process, yielding microscopic and macroscopic clarity issues.

diamond clarity scale

The GIA's clarity grades chart spans from FL (Flawless Diamond with No Inclusions), representing the highest quality, to I3, indicating the lowest diamond clarity grade with visible inclusions to the naked eye.

An effective strategy involves adhering to the SI2 GIA clarity grade or above while avoiding diamonds heavily impacted by clouds. Inclusions serve as a diamond's unique birthmarks and valuable markers when cross-referencing against a GIA or AGS report, especially if there's no laser inscription. In some instances, dealers might even favor VVS diamonds over Flawless ones due to their inclusion patterns.

Various permanent clarity enhancement techniques, like fracture filling or laser treatments, are available to enhance a diamond's quality. One such treatment, "fracture-filling diamonds," ameliorates clarity by addressing breaks or flaws. The use of lasers is also an option.

The inherent value of diamonds largely stems from their natural origin; altering the characteristics of a mined diamond significantly impacts its price, and such enhancements are clearly stated in a grading report.

Diamond Clarity Scale

The diamond clarity scale developed by GIA is divided into the following ranges:

diamond clarity scale

Flawless or FL: This category encompasses diamonds without blemishes or inclusions, representing the highest clarity grade.

Internally Flawless or IF: Within this grade, diamonds exhibit minimal external blemishes and no internal inclusions. It stands at the pinnacle of clarity.

Very Very Slightly Included 1 or VVS1: Diamonds with this grade possess an incredibly high clarity level. Inclusions are nearly impossible to spot without a microscope of 60-100X magnification, often requiring trained gemologists. As natural birthmarks, inclusions are as unique as fingerprints, contributing to the diamond's individuality.

Very Very Slightly Included 2 or VVS2: Similar to VVS1, this grade indicates high clarity. Inclusions are hard to identify without a jeweler's loupe; even gemologists might require a high-magnification microscope. A VVS2 diamond's inclusions are usually not easily discernible with a loupe.

Very Slightly Included 1 or VS1: Among the top clarity grades, VS1 diamonds are entirely eye-clean and esteemed as investment-grade, comparable to VVS stones. The line between VVS2 and VS1 is subtle, making them closely matched in quality.

Very Slightly Included 2 or VS2: Optimal for quality on a budget, VS2 offers excellent clarity. Diamonds in this range are eye-clean, particularly in sizes under 2 carats, making them an attractive choice for larger diamonds without compromising quality.

Slightly Included 1 or SI1: For 1 carat diamonds, SI1 can maintain eye-clean status when graded by GIA. In the 2 carat range, scrutinizing the clarity grade's impact on brilliance is essential. SI1 provides budget-friendly options with eye-clean appearances.

Slightly Included 2 or SI2: Eye-clean SI2 diamonds exist in the 1 carat range, depending on inclusion type and location. In the 2 carat range, finding truly eye-clean SI2 diamonds can be challenging. Close inspection is vital before purchase.

Included 1-3 (I1, I2, I3): This range represents the lowest clarity grades. Diamonds here are not eye-clean, often resulting in compromised brilliance and fire due to multiple flaws. While I1 could be acceptable for budget constraints, I2/I3 diamonds might not be advisable.

Diamond Clarity Factors

The clarity of a diamond can be influenced by five distinct factors: size, nature, number, relief, and location.

Size: The size of inclusions within a diamond directly impacts its clarity grade. Larger inclusions tend to result in lower clarity ratings. Furthermore, substantial inclusions can compromise the diamond's durability, making it advisable to avoid diamonds with lower clarity grades.

Nature: "Nature" pertains to the diamond's type and depth of inclusions. While inclusions penetrate the diamond's interior, blemishes are confined to its surface.

Number: The quantity of inclusions plays a significant role; more substantial inclusions or a higher number of blemishes lead to lower clarity grades. However, if these inclusions or blemishes are not discernible to the naked eye, they may not significantly impact the overall clarity rating.

Location: The position of inclusions or blemishes within the diamond is crucial. Proximity to the center of the table can notably affect clarity by interfering with the diamond's light reflection. Inclusions near the girdle might be difficult to perceive, but they could affect the diamond's integrity if located close to the surface.

Relief: "Relief" pertains to the prominence of an inclusion's visibility when observed within the diamond. Consequently, the greater the relief, the more pronounced the impact on the diamond's clarity grade.

Good & Bad Clarity Examples

Here are two examples of GIA graded SI1 clarity diamonds. When analyzing the clarity of a diamond, focus on three key sections in the grading report: 1) the comments section, 2) clarity characteristics, and 3) the key to symbols.

diamond clarity examples

The preferable choice between these two SI1 diamonds is the one on the left, which indicates fewer inclusions in the report than on the right. However, the diamond on the right is the better option. Here is why:

  1. The diamond on the right is graded with clarity based on clouds – a negative attribute.
  2. The diamond on the right features black crystals on the table.
  3. The diamond on the left has minor inclusions across its surface and generally lacks prominent black crystals.

Type of Inclusions & Blemishes

There are various types of diamond inclusions and blemishes, with several important ones to familiarize ourselves with:

Bearding: These inclusions occur along the diamond's girdle during cutting. Improper bruting can affect the clarity grade

Graining: Resulting from crystal growth within the diamond, widespread graining can cause a hazy appearance.

Cavity: Large cavities should be avoided, as they can impact the diamond's structure, formed during polishing due to crystal movement.

Crystals: Common inclusions in diamonds, black crystals like carbons are undesirable, while colorless white crystals are less problematic. Large single crystals are also less favored.

Clouds: Clouds often comprise a cluster of crystals concentrated in one area. Smaller clouds are generally not concerning, but larger ones can reduce brilliance, making the diamond appear hazy/cloudy. "Clarity grade is based on clouds" in a GIA report indicates high cloud presence.

Etch Channel: A tunnel-like hollow on the diamond's surface that extends internally, resembling a natural flaw rather than a laser-drilled treatment.

Feather: Fractures within a diamond can be problematic if significant and affect structural integrity or brilliance, especially if colored.

Manufacturing Remnant: A minor man-made error occurs during the cutting process with modern machinery. It is a residual effect and not a clarity enhancement.

Pinpoints: Small crystals (black or white) are generally less harmful inclusions and more desirable, particularly the white ones.

Twinning Wisps: Resulting from growth defects or distortion during formation, they can include pinpoints, crystals, feathers, etc. Harmless if small.

Chips: Often occur during cutting or polishing, with small chips not significantly impacting the diamond.

Indented Natural: Typically found near the girdle, this slight flaw results from polishing. It is usually benign and does not affect the diamond's brilliance.

Final Thoughts

The GIA's clarity grading scale is the industry benchmark for assessing a diamond's clarity. This scale is one of the renowned 4Cs – carat, cut, color, and clarity – and is paramount in influencing a diamond's valuation. The spectrum of diamond clarity ranges from Flawless to I3 (or Included 3). When selecting a diamond, focus on stones with a clarity grade of SI2 or higher for stones under 1 carat and SI1 or above for stones of 1.5 carats or more. Steer clear of diamonds solely graded based on the presence of clouds, as they can detract from the stone's aesthetics. Nonetheless, regular inclusions in the form of clouds are generally acceptable.