Ultimate Cut Grade: Extraordinarily Brilliant and Beautiful
Ultimate Diamond Cut Grade
8X® Lab-Grown Diamonds are awarded the highest achievement in precision diamond cutting. Recognized for their extraordinary brilliance and beauty, these lab-grown diamonds are meticulously analyzed and ultimately certified to be physically and optically excellent in eight critical factors of cut quality. Available shapes include round, oval, square, marquise, and pear.
Cut Grade
- Polish Excellent
- External Symmetry Excellent
- Proportions Excellent
- Optical Brilliance Excellent
- Fire Excellent
- Scintillation Excellent
- Optical Symmetry Excellent
- Hearts & Arrows Excellent
Physical Excellence
The first three 8X grading factors analyze the exactness of the physical surface, the facet shapes, and the angles.
#1 Polish
Skill and time are required to produce a well-polished, lab-grown diamond. GCAL gemologists examine every facet to ensure it is free of polish marks, burns, and scratches.
#2 External Symmetry
Master cutters identically shape each facet around the lab-grown diamond and ensure they are perfectly aligned.
#3 Proportions
Optical scanning technology measures each facet and angle to produce an accurate, to-scale diagram of every lab-grown diamond.
Light Performance Excellence
The next three 8X grading factors analyze the light handling ability of your lab-grown diamond. The combination of these factors is the essence of what makes any diamond visibly shine, dance, and sparkle from across a room.
#4 Optical Brilliance
Optical brilliance is the overall return of white light to the viewer. It is measured to the thousandth decimal place and is represented in this image. The white areas indicate light return/brilliance, and the dark blue areas indicate light loss.
#5 Fire
Fire results when white light travels through a diamond and is dispersed into its rainbow of spectral colors. These flashes of color contribute to sparkle and are best viewed as the lab-grown diamond moves.
#6 Scintillation
Scintillation refers to the dynamic flashes of light that occur when the lab-grown diamond or the observer moves, creating a sparkling effect. It encompasses both the intense bright spots of light and the contrasting dark areas.
Optical Excellence
The last two 8X grading factors scrutinize the craftsmanship and the precise alignment of the crown and pavilion facets in harmony to achieve aesthetic perfection.
#7 Optical Symmetry
Optical symmetry is visualized in this photograph of your lab-grown diamond taken in a specific-colored lighting environment. The evenness of the pattern illustrates the precision and uniformity of facet shapes and alignment.
#8 Hearts & Arrows
Precision faceting is visualized as Hearts & Arrows when round, brilliant-cut, lab-grown diamonds are viewed in specific lighting conditions. Each pattern is the result of superior facet placement and exact alignment. For Round Stones Only
For round stones only
Table %
54.0% to 58.0%
Depth %
59.8% to 62.2%
Crown Angle
34.0º to 35.0°
Pavilion Angle
40.6° to 41.0°
Star Length %
45% to 55%
Culet Size
None to Very Small
Girdle Thickness
Thin to Slightly Thick, Faceted
Lower Girdle Facet %
75% to 80%