GCAL 8X Cut Grade Lab Grown Diamonds
The Ultimate Standard in Diamond Excellence!
The Industry’s Most Exclusive Standard for Diamond Brilliance and Quality
GCAL’s 8X Ultimate Cut Grade represents the highest diamond-cut evaluation standard, requiring a diamond to achieve an “Excellent” rating across eight distinct criteria. Founded in 2001 by Donald Palmieri and located at 580 Fifth Avenue in New York City, GCAL has established this rigorous benchmark for both natural and lab-grown diamonds. This ensures that every certified stone exhibits exceptional brilliance, aesthetic appeal, and superior craftsmanship. The GCAL 8X® Ultimate Cut Grade lab-grown diamonds embody the pinnacle of modern diamond artistry, delivering unparalleled sparkle, precision, and ethical assurance. This exclusive grading system was developed to identify the elite diamonds in a marketplace where “Excellent” cut grades are increasingly common. While over 50% of Round Brilliant Cut diamonds receive an “Excellent” cut grade from traditional laboratories, less than 1% meet the stringent criteria for the 8X distinction. This unique standard caters to discerning consumers seeking the finest quality in diamonds.
Shapes Available in GCAL 8X Cut Grade Lab Diamonds
Round Brilliant
Oval Cut
Princess Cut
Pear Cut
Marquise Cut
The 8X Grading Factors
This system covers every aspect of diamond cut quality, from surface finish to how the diamond handles and returns light, and even the precision of its internal craftsmanship. Here’s a detailed breakdown of each factor:
Polish
External Symmetry
Proportions
Think of proportions as the blueprint behind the beauty. We’re talking angles, depth, crown height, and more—all perfectly measured to make the most of how light bounces around inside the stone. GCAL uses high-tech scanners to make sure everything is within a super-specific range. For round brilliants, for example, there’s even an ideal table size (usually 54–58%) and exact angles for max sparkle. A tiny difference can mean the difference between “meh” and “mesmerizing.”
| Proportion Parameter | Ideal Range |
|---|---|
| Table % | 54.0% – 58.0% |
| Depth % | 59.8% – 62.2% |
| Crown Angle | 34.0° – 35.0° |
| Pavilion Angle | 40.6° – 41.0° |
| Lower Girdle Facet Length | 75% – 80% |
| Star Length | 45% – 55% |
| Girdle Thickness | Thin to Slightly Thick, faceted |
| Culet Size | None – Very Small |
Optical Brilliance
Fire
Fire is that rainbow sparkle you see when light hits the diamond just right. You’ve probably caught that flash of color before and thought, “Is that real?” Yep—it is. And it happens because the facets are perfectly aligned and proportioned to split light into all those stunning colors.
Scintillation
Optical Symmetry
This digs even deeper than external symmetry—it’s about how well the inner facets of the diamond line up with each other. Under colored lighting, you can actually see the patterning. When the symmetry is spot on, everything comes together in a way that enhances both brilliance and beauty. You might not notice it at first, but your eyes definitely feel the difference.
Hearts & Arrows
