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GIA Unveils Framework for Grading Fancy Diamond Cuts February 20, 2025 (0 comments)
New York, NY--GIA Education has released a report on a new framework for grading the cut quality of fancy-shaped diamonds. According to GIA Education, the study focused on oval, pear, and marquise diamonds, which exhibit more complex appearance patterns than standard round brilliant.
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The report involved international trade participants and internal GIA observers who evaluated diamonds under standardized lighting. They rated features such as brightness, contrast, windowing, bow tie patterns, and crushed ice effects. GIA Education noted that while prominent windowing was consistently disliked, opinions on bow tie and crushed ice patterns varied.
The study employs three-dimensional virtual facet maps generated from diamond wireframe files to quantitatively visualize facet patterns and predict light behavior. According to the report, these maps are essential because fancy shapes require a grading system that addresses many more parameters than those used for standard round brilliants.
GIA Education concludes that an effective cut grading system for fancy shapes must combine precise 3D modeling with human observations to account for both fundamental appearance aspects and regional or personal taste differences.
Learn more in this report by GIA.
