(IDEX Online) – Grading reports produced by IGI will now offer a “light performance score” for round brilliant cut diamonds.
They’ll provide an overall score – low, moderate, high, superior or exceptional – for a stone’s light performance, together with separate scores for brightness, fire, and contrast, which combine to produce scintillation.
The International Gemological Institute (IGI), says its researchers used ray-tracing software to analyze light performance across a range of 12,474 round brilliant cut proportions sets spanning 18 table sizes.
