WHAT SETS THE 8X® APART FROM OTHER RADIANT BRILLIANT CUT DIAMONDS?
The 8X Ultimate Cut Grade was developed to distinguish the best of the best diamonds. In today’s market, less than 1% of all Radiant Brilliant Cut diamonds qualify as 8X. The GCAL 8X Ultimate Cut Grade gives discerning buyers a way to confidently select the most brilliant and beautiful diamonds, even when purchasing online, sight unseen.
THE GCAL 8X® ULTIMATE DIAMOND CUT GRADING SYSTEM
ENCOMPASSES ALL ASPECTS OF DIAMOND CUT QUALITY ASSESSMENT
PHYSICAL
EXCELLENCE
- 1Polish
- 2External Symmetry
- 3Proportions
LIGHT PERFORMANCE
EXCELLENCE
- 4Brilliance
- 5Fire
- 6Scintillation
OPTICAL
EXCELLENCE
- 7Optical Symmetry
- 8Shape Aesthetics
PHYSICAL EXCELLENCE
The first three of the 8X grading factors analyze the exactness of the physical surface, the facet shapes, as well as the angles.
POLISH
Skill and time are required to produce a well polished diamond. GCAL gemologists examine every facet to ensure it is free of polish marks, burns and scratches.
EXTERNAL SYMMETRY
Master cutters identically shape each facet around the diamond and ensure they are perfectly aligned. Only diamonds with precision faceting achieve a GCAL Excellent.
PROPORTIONS
Optical scanning technology measures each facet and angle to produce an accurate, to-scale diagram of every diamond.
| Table % : | 63% - 66.5% |
|---|---|
| Depth % : | 66% - 68.6% |
| Crown Angle : | 42.50 - 450 |
| Crown Height : | 12% - 13.2% |
| Pavilion Angle : | 570 - 620 |
| Pavilion Mains Angle : | 35° - 36.7° |
| Pavilion Depth : | 50.4% - 52.7% |
| Girdle Corner Width %: | 20% - 26% |
| Length to Width Ratio : | 1.40 – 1.47 |
| Girdle Thickness : | Thin - Thick |
| Culet Size : | None - Very Small |
| *Additional Parameters: | *Available upon request |
LIGHT PERFORMANCE EXCELLENCE
The next three of the 8X grading factors analyze the light handling ability of your diamond. The combination of these factors is the essence of what makes any diamond visibly shine, dance and sparkle from across a room.
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.
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 diamond moves.
SCINTILLATION
is the flashes of while light, or sparkle, produced when light is reflected from a diamond as it moves. This video shows the light returned from a single beam of light when your diamond is rotated in nine positions.
OPTICAL EXCELLENCE
The last two 8X grading factors scrutinize the craftsmanship and the precise alignment of the crown and pavilion facets to achieve aesthetic perfection.
OPTICAL SYMMETRY
is visualized in this photograph of your diamond taken in a specific colored lighting environment. The evenness of the pattern illustrates the precision and uniformity of facet shapes and alignment.
SHAPE AESTHETICS
The angles and shape outline are measured to confirm 8X® radiant cuts possess a refined, elongated rectangular shape with precise and symmetrically cut corners, and a desirable length-to-width ratio. The axis symmetry images shown here are part of these measurements
The dark area of blocked light return sometimes seen under the table of radiant cut diamonds is known as a "bowtie." The cutting parameters are designed to minimize this effect, with each stone evaluated to confirm a minimal bowtie, and ample light return throughout.
