How beautiful is a diamond?
The PGGL Light Behavior Certificate grades the very reason why diamonds are bought; their beauty. Using ImaGem’s VeriGem machine, PGGL measures and grades a diamond’s light behavior- namely its brilliance, sparkle, and intensity. The certificate lists numerical measures on overall light behavior, brilliance, sparkle and intensity with images that represent these features.

This service is available for loose diamonds and for diamonds that are set in jewelry*. The certificates are available in two formats; a full page format and a credit card size format.
PGGL uses ImaGem’s direct measurement of light behavior technology. This technology represents a new way to quantify a diamond’s beauty as seen by the human eye. These scientifically based measures are designed to match what the human eye sees when viewing diamonds under normal lighting conditions.
Diamonds with ‘high’ light behavior measures are gaining importance and demanding higher prices making light behavior a very useful tool to sell diamonds.
Customization is available for members of trade. Additional information is available upon request.

  • Direct Assessment of your diamond’s beauty.
  • Measure a diamond’s Light Behavior using Direct Measurement in just 30 seconds.
  • Precise and Repeatable results each time.
  • Issue reports as soon as grading is complete.
  • Grade mounted diamond jewelry for Light Behavior.
  • New way to buy and sell diamonds on the basis of their beauty.
  • Assures you of a more accurate description and valuation for insurance purposes.
  • An effective tool for comparing multiple diamonds.

Performance Specifications
Light Behavior: ±2% of Brilliance; ±2% of Sparkle; ±4% of Intensity – all with 2 sigma probability.

*Certain size restrictions may apply. Contact PGGL for additional information.