How To Choose a Diamond

When it comes to choosing a diamond, understanding the 4Cs - cut, color, clarity, and carat weight - is essential. The cut refers to how well the diamond has been shaped and faceted, directly impacting its brilliance and sparkle. Look for a diamond with an excellent or ideal cut grade to ensure maximum light performance.

Understanding the anatomy of a diamond is also crucial. A diamond consists of different parts, including the table (the top flat surface), the crown (the upper portion above the girdle), the girdle (the narrow band between the crown and pavilion), and the pavilion (the lower portion below the girdle). Light dispersion, also known as fire, occurs when light enters the diamond, reflects internally, and disperses into a spectrum of colors. Look for a diamond with a well-cut pavilion angle and crown height to maximize light dispersion and brilliance.




Diamond grading agencies evaluate the cut of round brilliant diamonds using a comprehensive grading system that considers various factors contributing to the diamond's overall cut quality and light performance. The grading system for round brilliant diamonds consists of the following components:

  1. Brilliance: This refers to the diamond's ability to reflect white light. This evaluation considers the diamond's proportions, including the depth and table size, which affect the amount of light entering and reflecting back from the diamond.

  2. Fire: Fire refers to the dispersion of white light into spectral colors, creating flashes of color. Grading depends on the diamond's ability to display fire by examining the quality of light dispersion achieved through the diamond's faceting arrangement and precision.

  3. Scintillation: Scintillation refers to the sparkle and pattern of light and dark areas observed when the diamond is in motion. Grading assesses how well a diamond exhibits scintillation by evaluating the contrast and distribution of light reflections throughout the diamond.

  4. Proportions: This includes the crown angle, pavilion angle, and overall depth, and these factors determine how well the diamond has been cut. These proportions significantly impact the diamond's ability to reflect and refract light optimally.

Based on these factors, a grading agency assigns a cut grade to round brilliant diamonds. The cut grades are as follows:

  • Excellent/Ideal: Diamonds with excellent cut grades possess the highest level of light performance, displaying exceptional brilliance, fire, and scintillation.

  • Very Good: Diamonds with very good cut grades exhibit excellent light performance, with slight variations in brilliance, fire, or scintillation that may be observed by experts.

  • Good: Diamonds with good cut grades display satisfactory light performance, although they may not exhibit the same level of brilliance and fire as higher grades.

  • Fair: Diamonds with fair cut grades show noticeable variations in light performance, often resulting from proportions and faceting that do not optimize light reflection.

  • Poor: Diamonds with poor cut grades have significant deviations from the optimal proportions and faceting, resulting in diminished light performance and overall visual appeal.

Fancy cut diamonds (i.e. not round)

The Gemological Institute of America (GIA) and other grading agencies do not assign formal cut grades to fancy shape diamonds, such as princess, cushion, emerald, or radiant cuts, in the same way as for round brilliant diamonds. This is primarily due to the unique faceting styles and variations found in fancy shape diamonds, which make it challenging to establish a standardized cut grading system that applies universally to all fancy shapes.

Unlike round brilliant diamonds, which have specific proportions and facet arrangements that contribute to their overall cut quality and light performance, fancy shape diamonds exhibit more diverse cutting styles and facet patterns. Evaluating fancy shape diamonds requires a more nuanced and individualized approach that takes into account their unique characteristics.

Instead of a formal cut grade, the grading reports provide important information on a diamond's shape and cutting style, as well as grading factors specific to each fancy shape. These factors may include aspects such as brilliance, fire, scintillation, symmetry, polish, and the overall visual appeal of the diamond.

While the absence of a standardized cut grading system for fancy shape diamonds can make the selection process more subjective, it also allows for a greater appreciation of the unique beauty and individuality that these shapes offer. When considering a fancy shape diamond, it is advisable to examine its grading certificate for information on its specific characteristics, and work with a knowledgeable jeweler who can provide guidance based on their expertise and understanding of fancy shape diamonds. This way, you can find a diamond that captures your desired combination of shape aesthetics, brilliance, and overall visual appeal.


Color is another important factor to consider. Diamonds are graded on a color scale ranging from D (colorless) to Z (light yellow or brown). Diamonds in the colorless to near-colorless range (D to G) are highly sought after for their brilliance, while those in the slightly colored range (H to J) can offer excellent value without compromising beauty.  Of course, these are just general guidelines, and beautiful diamonds can also be found in the deeper, warmer grades as well.  Many diamonds that aren't in the colorless grades can present as very white face up in the setting, often the color is mostly seen from the side.


Clarity refers to the presence of internal or external flaws, known as inclusions and blemishes, respectively. The clarity scale ranges from flawless (no inclusions or blemishes visible under 10x magnification) to included (inclusions visible to the naked eye). Many people opt for a diamond with a clarity grade that ensures the imperfections are not readily visible to the naked eye, but even highly included diamonds can be gorgeous and are often very unique.  A few well placed inclusions can make your diamond uniquely yours.

Quick & Easy Diamond Series: GIA Diamond Clarity | Freedman Jewelers -  Freedman Jewelers

The clarity scale ranges from Flawless (FL) - indicating no inclusions or blemishes visible under 10x magnification - to Included (I3) - where inclusions and blemishes are visible to the naked eye. In between these extremes, there are various grades that determine the clarity of a diamond.

Flawless (FL) and Internally Flawless (IF) diamonds are exceedingly rare and highly sought after for their remarkable clarity. Very Very Slightly Included (VVS1 and VVS2) diamonds contain minute inclusions that are extremely difficult to detect even under magnification.  Very Slightly Included (VS1 and VS2) diamonds will have inclusions that are easier to find under magnification, but these will not be visible to the naked eye.

Slightly Included (SI1 and SI2) diamonds have noticeable inclusions that may be visible under 10x magnification but are typically not visible to the naked eye as the inclusions typically get lost in the sparkle.  If you know where to look, you might be able to see an inclusion when searching for it.  I really like this grade of diamond since it gives each diamond a unique personality or fingerprint. Included (I1, I2, and I3) diamonds have inclusions that are visible to the naked eye, with I3 having the most noticeable inclusions.  The only inclusions I would generally recommend against are "clouds", which can seem to blur the sharpness of the sparkles.

It is important to note that clarity alone does not solely determine a diamond's beauty. In many cases, diamonds with lower clarity grades can still possess exceptional beauty and brilliance.  Flawless diamonds can be very beautiful, but a beautiful diamond with unique inclusions is distinctive and one of a kind. They also have the advantage of being more affordable than a flawless diamond of the same size.

By understanding the diamond clarity scale and considering factors such as the size, position, number, and visibility of inclusions, it is possible to find a diamond that strikes the perfect balance between clarity and value for your personal preferences and budget.