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Join IGI & Rapaport May 15 for ‘Seeing the Light:’ All about light performance in diamonds

Following the recent launch of IGI’s new science-based Light Performance Reports for round brilliant diamonds John Pollard, Senior Director of Education for IGI, and Garry Holloway, developer of the Ideal-Scope, will speak with Rapaport’s Leah Meirovich about what light performance is, how it can add value beyond the 4Cs, and why light performance reports can be helpful for selling diamonds.

The LinkedIn Live session will take place on Wednesday May 15th at 10:00 am EDT (USA). Brought to you by IGI, the session will shed light on an entirely different way to identify the diamonds which best generate brightness, fire, contrast and scintillation.

Rapaport GemTalks

Key highlights

  • What is light performance is why is it crucial?
  • How it impacts your diamond’s appearance in various environments
  • Insights beyond the 4Cs of grading
  • The differences between approaches and what sets IGI’s apart
  • How light performance education is useful for consumers and trade members

The IGI Light Performance Report

The IGI Light Performance Report showcases round brilliant cut diamonds with exceptional optical qualities. The IGI system calculates values for each diamond to provide a primary score, indicating the overall strength of Light Performance, along with sub-component scores for Brightness, Fire, and Contrast.

Diamonds of the same shape can exhibit different visual characteristics. IGI’s new light performance assessment supplements traditional diamond grading by communicating the unique aesthetic story each diamond tells, with scientific analysis which explains its appeal.

IGI Light Performance Graph

In the IGI system: “Brightness” refers to all reflected and refracted white light. “Fire” is dispersed light seen as flashes of color. “Contrast” is the balance and intensity of light and dark areas at common viewing distances. The primary “Light Performance” score indicates the overall strength of brightness, fire, and contrast as they combine to produce scintillation; considered by many to be a diamond’s most appealing quality.

“Light performance is directly connected to a diamond’s appeal,” stated IGI CEO Tehmasp Printer. “In recent years we have seen increasing interest in expanded performance analysis. IGI has responded by creating an easy to understand, science-based light performance report along with cutting guidelines for diamond producers, empowering them to target the best results. We are pleased to support manufacturers, sellers, and buyers of high performing diamonds with detailed information on these popular aspects of diamond beauty.”

IGI Light Performance Grading Methodology

The system was developed by IGI researchers using ray-tracing software and slope proportions logic to assess a wide range of parametric data sets for round-brilliant cuts spanning 18 table sizes. Parameters judged to have exceptional performance were further assessed using structured light environment renderings and physical science to calculate scores for commonly described aspects of diamond beauty.

The scores are supported with a computer-generated map of the diamond in an instrument called ‘Ideal-Scope;’ a structured light environment which reveals overall light return, light leakage, and contrast. That image conforms to the diamond’s actual parametric measurements, permitting further expert analysis of fundamental light behavior.

More information about the system, as well as light performance cutting guidelines for diamond manufacturers are available online at

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