What Is Diamond Cut Quality?

Diamond Cut Quality is an important criterion for determining and valuing a diamond. Understanding diamond cut quality is essential to know how to buy a perfect diamond. In the article below, Jemmia Dimond will share detailed information about Diamond Cut Quality.

What is Diamond Cut Quality?

Diamond Cut Quality is the quality of a diamond’s cut. This is one of the most important factors determining the beauty and brilliance of a diamond. It reflects how a diamond is cut from the rough stone, affecting its ability to interact with light. Cut quality is not only related to the external shape but also includes the precision of proportions and cutting angles, helping the diamond reflect light optimally.

• Brilliance: This is the ability of a diamond to reflect white light when light enters it. When light enters the top of the diamond, it is reflected through the pavilion facets and then returns to the top. A well-cut diamond will reflect most of the light back to the viewer’s eye, creating sparkle. If cut too shallow or too deep, light will scatter out through the bottom, reducing brilliance and creating dark areas.
• Fire: This is the effect in which a diamond disperses white light into rainbow colors. Fire occurs when a diamond reflects light at different angles, especially under low light sources. A perfectly cut diamond will create this dispersion optimally, making the diamond radiant with many colors.
• Scintillation: Scintillation is the sparkle a diamond emits when it moves, including the balance between bright areas (white light) and dark areas (dark areas). The contrast between these areas, when the diamond moves under light, creates the sparkling appearance we see. A diamond with good scintillation will clearly show changes in light and shadow when rotated under light.

3 factors—brilliance, scintillation, and fire—directly affect the beauty and value of a diamond

Therefore, these factors not only determine the quality of the cut but also directly affect the beauty and value of the diamond.

Factors affecting Diamond Cut Quality

AGS has pointed out that: “A perfectly cut diamond not only sparkles more but also retains its beauty and value longer than a diamond with poor cut quality.” Diamond cutting is classified into many grades and plays a very important role in optimizing a diamond’s brightness and brilliance.

Different grading organizations, including AGS and GIA, use different names to classify cut quality. For example, AGS uses a scale from 0 to 10 for evaluation, with 0 being ideal cut and 10 being poor cut. This scale helps buyers understand and choose the diamond with the most suitable cut quality.

Cut grading is based on important factors to ensure that the diamond is cut in a way that optimizes brilliance and fire. Factors affecting the beauty and light reflection ability of a diamond include:

• Cut grade: Determines the overall quality of the cut.
• Table percentage: The percentage of the table width compared to the overall width of the diamond.
• Depth percentage: The percentage of the diamond’s depth compared to its diameter.
• Crown height and angle: Affects how light enters and reflects back from the diamond.
• Pavilion depth and angle: Influences how light is retained or leaks through the bottom.
• Girdle: The largest part of the diamond separating the upper and lower sections.
• Star length: Measures the length of the small facets connecting from the table to the top of the diamond.

Factors affecting Diamond Cut Quality

Diamond Cut Quality rating scale of the American Gem Society (AGS)

AGS uses a scale from 0 to 10 to evaluate diamond cut quality, with 0 being the best. Specifically:

• 0 points: Ideal Cut – Considered the most perfect level, achieving the maximum in balance, light reflection, and brightness.
• 1 point: Excellent Cut – Nearly perfect, but may have very slight deviations.
• 2 points: Very Good Cut – Only small differences compared to the excellent level; however, the diamond still has good sparkle.
• 3 – 4 points: Good Cut – Still reflects light quite well, but not as optimally as the higher levels.
• 5 – 7 points: Fair Cut – Light reflection is significantly reduced, and the diamond sparkles less.
• 8 – 10 points: Poor Cut – Poor light reflection, lacking brilliance, and the diamond may appear dull.

See more: Which diamond color is the most expensive? Which country is the most expensive?

Usually, only round-cut diamonds are given a cut grade on the diamond certificate. However, each diamond shape has its own ideal cut range and values, as well as ranges for the factors affecting the cut of the diamond.

In fact, Diamond Cut Quality is an important standard alongside other standards such as Carat, Color, and Clairity. Be sure to learn carefully when buying diamonds!