Diamond Cuts

By Carats

Pinnacle Optical Light Return • 8X Ultimate Cut

GCAL Diamond Certification.
Zero-Tolerance Grading & Optical Precision.

Founded in New York in 2001 by Donald A. Palmieri and now powered by Sarine Technologies, GCAL (Gem Certification & Assurance Lab) is the only diamond grading laboratory that guarantees its grades with an enforceable money-back cash warranty and sets the world standard with the 8X® Ultimate Cut Grade.

What Is 8X Cut? All Certification Labs

8 Aspects of Cut Perfection Gemprint® Optical DNA 100% Backed Cash Guarantee

GCAL 8X Ultimate Cut Certified Lab Grown Diamond

GCAL 8X® Certified

GEMPRINT® SECURED

New York, USA

✦ The Optical Pinnacle ✦

What Is the GCAL 8X® Ultimate Cut Grade?

Traditional labs like GIA and IGI grade cut based mostly on mathematical 2D proportion tables. GCAL went revolutionary by testing actual 3D physical light performance across 8 separate criteria:

1. Polish

Optical Polish

Microscopic smoothness examined under 100x magnification to eliminate wheel marks and micro-scratches.

2. Symmetry

External Symmetry

Facet junction alignment and table-to-culet centering verified via electronic Sarine mapping.

3. Proportions

Proportions Analysis

Tightest tolerance mathematical angles that channel 99%+ of light through the crown.

4. Optical Brilliance

White Light Return

Direct measurement of white light returned to the eye; zero light leakage or windowing allowed.

5. Optical Fire

Spectral Dispersion

Evaluation of rainbow spectral flashes caused by light bending through the diamond facets.

6. Scintillation

Sparkle Pattern & Contrast

Dynamic flashes of light as the diamond moves under direct spot lighting.

7. Optical Symmetry

Internal Light Balance

Evaluates mirror-image internal reflection and uniform contrast distribution.

8. Hearts & Arrows

Facet Craftsmanship

Perfect 8 hearts and 8 arrows visible through specialized gemological viewers.

The Zero-Tolerance 8X Rule

If a diamond earns "Excellent" in 7 categories but receives "Very Good" in just 1 category, it fails to achieve the 8X grade. Less than 1% of all lab grown diamonds meet this ultra-rigorous threshold.

✦ Patented Security ✦

Gemprint®: The Unique Optical DNA of Your Diamond

Every GCAL certified diamond comes registered with Gemprint®, a patented biometric laser verification system used by international law enforcement and insurance registries since 1974.

Non-Invasive Laser Record

A low-power laser shines into the diamond, recording its light refraction pattern. No two diamonds produce the same Gemprint, even if cut from the exact same crystal.

Insurance Premium Discounts

Major jewelry insurance companies offer up to a 10% annual discount on policy premiums for Gemprint-registered diamonds.

Anti-Switching Verification

When leaving your diamond with a jeweler for cleaning or setting, a quick Gemprint rescan proves beyond doubt that your exact stone was returned.

GCAL by Sarine

Certificate & Warranty

Cash Backed

GCAL is the only laboratory in the world that stands behind its grading with a written cash guarantee. If any grade is found inaccurate upon second review, GCAL compensates the financial difference.

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