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GCAL Develops All New Eight-Factor Diamond Cut-Grading Standard |  March 23, 2021 (0 comments)


New York, NY—Gem Certification & Assurance Lab (GCAL) has announced a new cut grading evaluation based on eight factors. 8X™, the first new cut grade evaluation to be introduced to the industry in decades, incorporates five more criteria than the typical three factors of cut quality grading. All eight factors are required to achieve a grade of Excellent in order for the stone to receive the Excellent grade. 

GCAL developed the eight-point standard after years of extensive research, studying hundreds of thousands of diamonds, and gathering data to identify the strict, exacting tolerances needed to achieve the ultimate precision cut diamond. The eight aspects of cut quality assessment that must each receive a grade of Excellent to qualify as an 8X™ diamond are: 1) polish, 2) external symmetry, 3) proportions, 4) optical brilliance, 5) fire, 6) scintillation, 7) optical symmetry and 8) hearts & arrows.  

Grading factors one through three (polish, external symmetry and proportions) focus on physical precision. They analyze the exactness of the physical surface, facet shapes, and angles.  The precise dimensions required to produce the most ideal round brilliant cut have been analyzed for decades, and only natural and lab grown diamonds within the strict and narrow tolerances outlined in the image below achieve an Excellent Proportion grade.

Grading factors 4 through 6 (optical brilliance, fire, and scintillation) focus on and analyze the light-handling ability of a natural and lab-grown diamond. These carry significant consumer importance because it is the combination of these factors that make any diamond visibly shine and sparkle.

Grading factors 7 and 8 (optical symmetry and hearts & arrows) focus on optical precision; the craftsmanship of the crown and pavilion facets in harmony.

Why the 8X was developed. GCAL says that while diamonds must meet exacting standards in cut, polish, and symmetry in order to receive an "excellent" cut grade in the industry's existing cut evaluation standards, the "excellent" grade still encompasses a range of tolerances. Indeed, tolerances were the major sticking point when the existing cut grade scales were being developed in the early 21st century: would the best cut proportions mirror the industry standard "ideal" cut developed by Marcel Tolkowsky in 1917, or could a stone have slightly different proportions from Tolkowsky and still look equally as beautiful? And although cut is the most complex of the Four C’s to evaluate, gem labs have struggled to consistently quantify the optimal light emissions of brilliance, fire and scintillation. After all, diamond and gem grading remains to this day part art, part science.

GCAL addresses the science, the more quantifable. “8X™ is truly the ultimate achievement in precision diamond cutting,” says Don Palmieri, founder and president of GCAL.  “It’s less about distinguishing our lab and more about providing a platform for the world’s premier diamond manufacturers to distinguish their products from all others.” 

COO Angelo Palmieri added, “A great many manufacturers have shared with us their frustration of having their precision-cut diamonds judged on par with diamonds of a lesser cut quality, yet graded equally. He also pointed out that technology and diamond cutting techniques have improved, resulting in more brilliant and beautiful diamonds in today’s market. 

“It was time to honor that craftsmanship. Consumers can easily identify the best color and clarity. Now the pinnacle in cutting can now be identified scientifically.”

To support the program, GCAL is introducing the 8X Ultimate Diamond Cut Grade Guaranteed Certificate.The 8X logo will be inscribed on each diamond’s girdle, and appear prominently on the print and digital certificates. Print 8X certificates will feature rich black front and back covers, and are printed on high quality, tear-proof and water-proof material.  Consumers will be able to scan a QR Code to view the digital cert online. 

The 8X certificate cover, above, and inside, below.

Every 8X Natural and Lab Grown Guaranteed Diamond Certificate will also include:

To view the grading scales for each of the 8X grading factors, please visit GCAL’s website at  For more information, please call GCAL at 212-869-8985, or email

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