Stuller GCAL 8X Lab-Grown Diamonds
A Cut Above the Rest
GCAL 8X Ultimate Cut Grade Lab-Grown Diamonds represent the highest standard in precision diamond cutting, achieving excellent grades in all eight critical factors of cut quality. This elite standard ensures exceptional light performance, delivering the brilliance, fire, and sparkle customers instantly recognize.
8X Lab-Grown Diamonds
Backed by GCAL (Gem Certification & Assurance Lab) certification and enhanced with interactive visuals, such as 360-degree videos and light performance imaging, each lab-grown diamond gives you the confidence to showcase and sell with ease. Available in a range of popular shapes, Stuller’s 8X assortment delivers a premium lab-grown option designed to stand apart.
Your Advantage — Backed by Stuller
Confidence, Quality, and Support — All in One Place
Choosing GCAL 8X Lab-Grown Diamonds through Stuller means more than sourcing a premium product — it means gaining a trusted partner in every sale. With everything from verified quality to dedicated support, Stuller equips you with the tools and expertise needed to confidently present and sell with ease.
GCAL-Certified Quality: Every 8X lab-grown diamond includes a detailed report with advanced imaging and performance videos.
Interactive Selling Tools: Showcase brilliance with 360-degree views, fire, and scintillation videos to enhance customer confidence.
Expert Support: Stuller’s diamond and gemstone team is here to help with sourcing assistance and guidance.
Reliable Availability: Stuller offers an expanded assortment across popular shapes to meet a wide range of customer preferences.
8X Lab-Grown Diamond Shapes
Explore the full range of GCAL 8X Lab-Grown Diamond shapes — each engineered for optimal light performance and visual beauty. From classic silhouettes to modern cuts, every shape is analyzed for symmetry, proportions, and brilliance to meet the highest standards of the 8X designation.

ROUND 8X
Crafted to perfection, these feature super ideal proportions and hearts & arrows precision, delivering the perfect combination of brilliance, fire, and scintillation.

OVAL 8X
Graceful, curved outline and desirable ellipse shape with minimal bow-tie effect, proportions are optimized to deliver brilliance, fire, and balanced light return.

SQUARE 8X
Perfectly square with pristine corners and precise symmetry, proportions are engineered to deliver exceptional brilliance and fire in a beautifully balanced cut.

MARQUISE 8X
Tapered elliptical shape features an attractive symmetrical outline, defined pointed tips, and minimal bow-tie, analyzed to ensure bright light return throughout.

PEAR 8X
Elegant teardrop shape features a symmetrical outline, even sides, and minimal bow-tie effect, proven to deliver brilliance, fire, and sparkle throughout.

RADIANT 8X
Precisely cut refined rectangular shape features symmetrical corners, crafted in proportions that minimize bow-tie effect and maximize light return.
8 Excellent Reasons to Choose 8X Lab-Grown Diamonds
| 1. Polish | EXCELLENT |
| 2. External Symmetry | EXCELLENT |
| 3. Proportions | EXCELLENT |
| 4. Optical Brilliance | EXCELLENT |
| 5. Fire | EXCELLENT |
| 6. Scintillation | EXCELLENT |
| 7. Optical Symmetry | EXCELLENT |
| 8. Shape Aesthetics | EXCELLENT |
8X Grading Factors
GCAL 8X Lab-Grown Diamonds are set apart by their ability to achieve excellence across all eight critical grading factors — a rare combination of physical precision, light performance, and optical symmetry. Together, these elements define how a diamond looks, performs, and captivates the eye.
From the exactness of each facet to the way light reflects and disperses, every detail is measured and verified. The result is a diamond that doesn’t just meet expectations — it delivers maximum brilliance, fire, and sparkle from every angle.
The first three of the 8X grading factors analyze physical precision — the exactness of the physical surface, the facet shapes, as well as 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 diamond and ensure they are perfectly aligned. Only lab-grown diamonds with precision faceting achieve a GCAL excellent grade.
#3 Proportions
Optical scanning technology measures each facet and angle to produce an accurate, to-scale diagram of every lab-grown diamond.
The next three of the 8X grading factors analyze the light-handling ability of a diamond. The combination of these factors is the essence of what makes any lab-grown diamond visibly shine, dance, and sparkle bright enough to be seen from across a room.
#4 Optical Brilliance
This factor is the overall return of white light to the viewer. It is measured to the thousandth decimal place. White areas indicate light return/brilliance, while dark blue areas indicate light loss.
#5 Fire
This factor 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. Each 8X lab-grown diamond certificate has a video demonstrating its fire.
#6 Scintillation
This factor refers to to the flashes of white light, or sparkle, produced when light is reflected from a diamond as it moves. Each 8X lab-grown diamond certificate has a scintillation video demonstrating the light returned from a single beam of light when the stone is rotated.
The last two 8X grading factors scrutinize the optical precision — the craftsmanship and the precise alignment of the crown and pavilion facets in harmony to achieve aesthetic perfection.
#7 Optical Symmetry
This factor is visualized in a photograph of the 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 Shape Aesthetics
This factor analyzes features including axis length and axis width which are unique to Oval, Square, Marquise, Pear, and Radiant lab-grown diamonds. Hearts & Arrows is the precision faceting for Round lab-grown diamonds.
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Every GCAL 8X Lab-Grown Diamond is designed to help you sell with confidence and stand out in a competitive market. Explore Stuller’s 8X assortment today and discover how offering the highest standard in cut quality can elevate your inventory, strengthen customer trust, and drive more sales.
Diamond and Gemstones Sales Support
For everything from sourcing and matching to special orders and guidance, our team of industry experts is ready to help you find the perfect stone for every job. Contact the Diamond and Gemstone Sales Support Team at 800-877-7777, option 5.