When purchasing a yellow diamond, grading is an important factor to consider. Grading helps determine a yellow diamond's quality, rarity, and value, making it an essential part of the diamond-buying process.

But how does grading yellow diamonds work?

In this blog, we'll take a look at the grading process, from the Four Cs (color, clarity, cut, and carat weight) to the different grading scales used for yellow diamonds.

The Four Cs Of Yellow Diamond Grading

Grading Yellow Diamonds Work

When grading yellow diamonds, four key factors are considered: color, clarity, cut, and carat weight. These factors, also known as the Four Cs, can greatly impact the beauty and value of a yellow diamond.


The color of a yellow diamond is perhaps the most important factor in determining its value. Unlike other diamond colors, where a lack of color is desirable, the intensity of the yellow hue in a yellow diamond makes it unique and valuable.

Yellow diamonds are graded on a scale that ranges from faint yellow to fancy vivid yellow. The grading is based on the intensity and saturation of the yellow color, with fancy vivid yellow being the most rare and valuable.

Factors that affect the color grade of a yellow diamond include the presence of other colors, such as brown or green, the intensity of the yellow hue, and the overall saturation of color.


The clarity of a yellow diamond refers to the presence of internal and external flaws, known as inclusions and blemishes. The fewer and less visible these flaws are, the higher the clarity grade of the diamond.

Yellow diamonds are graded on a scale that ranges from included to flawless. The clarity grade is determined by the size, location, and type of inclusions or blemishes present.

Factors that affect the clarity grade of a yellow diamond include:

  • The size and location of inclusions.
  • The type of inclusions.
  • The presence of surface blemishes.


The cut of a yellow diamond refers to the proportions, symmetry, and polish. A well-cut yellow diamond will have optimal light reflection, resulting in a brilliant and lively appearance.

Yellow diamonds are graded on a scale that ranges from poor to excellent. The cut grade is determined by factors such as the depth and symmetry of the diamond, as well as the overall polish.

Factors that affect the cut grade of a yellow diamond include:

  • The depth and symmetry of the diamond.
  • The proportions of the diamond.
  • The overall polish.

Carat weight

The carat weight of a yellow diamond refers to its size and weight and is often the most easily recognizable aspect of a diamond's value.

Yellow diamonds are graded on a scale that ranges from less than 1 carat to 5 carat or more. The actual weight of the diamond determines the carat weight grade.

Factors that affect the carat weight grade of a yellow diamond include the actual weight of the diamond, as well as the size and shape of the diamond.

The Process Of Grading Yellow Diamonds

Grading Yellow Diamonds

Now that we've discussed the Four Cs of yellow diamond grading, let's dive deeper into the grading process itself.

Diamond Grading Labs

Yellow diamonds are graded by independent third-party laboratories, such as the Gemological Institute of America (GIA) and the American Gem Society (AGS). These labs use state-of-the-art equipment and highly trained gemologists to analyze each diamond's unique characteristics.

Grading a yellow diamond can be lengthy, as each aspect of the diamond's appearance and physical properties must be evaluated and analyzed.

Grading Tools and Techniques

The tools and techniques for grading yellow diamonds are highly specialized and sophisticated. Microscopes, spectrometers, and other advanced equipment are used to closely examine the diamond's color, clarity, cut, and carat weight.

In addition to high-tech equipment, experienced gemologists use their trained eyes to assess the diamond's overall appearance and beauty. They look for any blemishes, inclusions, or other imperfections that could affect the diamond's value.

Grading Criteria and Standards

When it comes to grading yellow diamonds, some specific criteria and standards must be followed. Each lab has its own set of guidelines, but the overall grading system is generally consistent across the industry.

For example, the GIA uses a scale ranging from D (colorless) to Z (light yellow or brown). The AGS uses a scale that ranges from 0 (the best) to 10 (the worst) for cut, color, and clarity.

These grading criteria and standards ensure that each diamond is accurately assessed and valued. They provide a consistent framework for evaluating diamonds, regardless of origin or market.

The 6 Color Intensity Of Yellow Diamonds

Yellow diamonds are considered a type of colored diamond and are given the "Fancy" grade when they fall outside the D-to-Z range of colorless to light-yellow diamonds. A yellow diamond must display more color than the Z masterstone to receive a Fancy grade. The GIA Colored Diamond Grading System categorizes yellow diamonds into one of six color grades: 

  1. Fancy Light
  2. Fancy
  3. Fancy Dark
  4. Fancy Deep
  5. Fancy Intense
  6. Fancy Vivid

The presence of nitrogen within a diamond is responsible for its yellow appearance. The amount of nitrogen present determines the degree of yellow color. In contrast, colorless diamonds typically have very little or no nitrogen, resulting in a lack of noticeable color.


In conclusion, understanding the intricacies of grading yellow diamonds is crucial for anyone purchasing or evaluating these exquisite gemstones. The Four Cs of yellow diamond grading - color, clarity, cut, and carat weight - play a significant role in determining a yellow diamond's value and beauty. 

The grading process, carried out by reputable diamond grading labs using specialized tools and techniques, follows strict criteria and standards to ensure accuracy and consistency.

By understanding the grading process and the factors that affect a yellow diamond's value, you can make informed decisions when purchasing or evaluating these unique gemstones.


What is the best clarity for yellow diamonds?

Yellow diamonds with a Fancy color grade are typically free from visible blemishes or inclusions. However, those with eye-visible flaws, graded as I1, can be found at a significant discount. Naturally, diamonds with higher clarity grades such as VVS, IF, or F will command a higher value than those with small inclusions graded as S.

Are yellow diamonds high quality?

Yellow diamonds of exceptional quality, with a diamond cut grade of VG/VG or higher and a clarity grade of VS1 or higher, are highly sought as investment pieces. This is especially true for diamonds above 2.00 carats and with a high intensity color grade of Fancy Intense or Fancy Vivid. In addition to the rising trend of exquisite diamonds and colored diamond jewelry, many economists now consider these exceptional yellow diamonds as recommended investment pieces.

How does grading yellow diamonds work?

The grading of yellow diamond colors is based on the depth and intensity of their hue. Diamonds with lighter colors are graded as Faint or Fancy Light and are less expensive. On the other hand, those with more intense hues are graded as Fancy Intense or Fancy Vivid, and they are much more valuable, commanding a higher price.