The Gemological Institute of America is developing a system to evaluate the cut of fancy-shaped diamonds, GIA distinguished research fellow James Shigley tells JCK.
“We want to determine what constitutes a good fancy cut and what doesn’t,” Shigley says. “What is an acceptable shape for a pear, or an oval, or a marquise?”
To that end, GIA conducted a series of observation tests at the most recent GemFair in Tucson, gauging attendees’ reactions to different types of marquise, oval, and pear shapes. Any evaluation system will likely be a mixture of both mathematical calculations and observational tests, which is how the GIA developed its round brilliant cut grade, Shigley says.
Even so, Shigley isn’t sure the lab will devise a grading system for fancies.
“I’m not certain we will end up with a grade,” he says. “We just don’t know that yet. We are doing our due diligence.”
He adds that the GIA will look to the trade for input, and “recognizes there is a lot of experimentation [with fancy cuts].”
Wherever the system ends up, Shigley says the GIA doesn’t want to take a decade to finish its research, as it did with its round brilliant cut grade.
“We want a much shorter timeline,” he says.