WHAT SETS THE 8X™ APART FROM OTHER EX/EX/EX DIAMONDS?

The 8X Ultimate Cut Grade was developed to distinguish the best of the best diamonds. In today’s market, more than half of all Round Brilliant Cut diamonds are given ‘Excellent’ Cut grades, but less than 1% of those 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

  • 4Optical Brilliance
  • 5Fire
  • 6Scintillation

OPTICAL
EXCELLENCE

  • 7Optical Symmetry
  • 8Hearts & Arrows
8X™ is the ultimate achievement in precision diamond cutting. Only extraordinarily brilliant and beautiful diamonds achieve EXCELLENT grades in all EIGHT aspects of CUT quality assessment.

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.

Decades of meticulous mathematical calculations have determined that these are the narrow proportion ranges required to produce superior Ideal round brilliant cut diamonds.
Table % : 54.0% - 58.0%
Depth % : 59.8% - 62.2%
Crown Angle : 34.0 0 - 35.00
Pavilion Angle : 40.6 0 - 41.00
Lower Girdle Facet Length : 75% - 80%
Star Length : 45% - 55%
Girdle Thickness : THIN TO SLIGHTLY THICK, faceted
Culet Size : NONE - VERY SMALL

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 white 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 lab grown 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 in harmony, to achieve aesthetic perfection.

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..

HEARTS & ARROWS

Precision faceting is visualized as Hearts & Arrows when round brilliant cut diamonds are viewed in specific lighting conditions. Each pattern is the result of superior facet placement and exact alignment.

ONE LOCATION. ONE STANDARD. GRADED IN THE USA.