The Shape of Things The Gemological Institute of America is developing a system to evaluate the cut of fancy-shape diamonds, including pears, ovals, and marquises, GIA distinguished research fellow James Shigley tells JCK. “We want to determine what constitutes a good fancy cut and what doesn’t,” Shigley says. In February, GIA conducted a series of observation tests at the American Gem Trade Association GemFair in Tucson, Ariz., gauging attendees’ reactions to different types of marquise, oval, and pear shapes. Any evaluation system will likely be a blend of both mathematical calculations and observational tests—the same way the GIA developed its round brilliant cut grade, which it unveiled in 2005. But Shigley, who helped formulate the grading system for rounds, isn’t certain the lab will devise a grade for fancies. “We just don’t know that yet,” he says. “