GIA has updated how it describes nacre quality stated on all GIA pearl classification reports, replacing the previous broad terms “Acceptable” and “Unacceptable” with GIA’s established traditional scale: Excellent, Very Good, Good, Fair, and Poor.
Previously, “Acceptable” denoted “expected commercial nacre quality, in terms of thickness, layering and condition,” while “Unacceptable” denoted “poor quality nacre that may impact durability, such as thinness, chalkiness or damage.”
Exceptional vs. Commercial
Prompted by observations and requests from members of the global pearl trade, the new scale broadens the grading range, allowing for distinctions between Excellent nacre quality and commercial nacre quality. The new scale provides greater consistency within the report, being more aligned with other quality factors.
“Nacre formation plays a critical role during a pearl’s growth, as its structure influences other value factors such as size, shape, luster, and surface quality. Nacre thickness and continuity also affect the pearl’s durability,” said Tom Moses, executive vice president and chief laboratory and research officer. “This update on the nacre quality scale provides improvement to the existing nacre quality description for the GIA 7 Pearl Value Factors classification system that better serves our clients.”
GIA’s Pearl Classification Reports
With GIA’s pearl classification service, the nacre of a pearl, strand or other item will be evaluated based on the degree of eye-visible movement (nacre variation) found on either the surface or sub-surface layers of nacre, in addition to the post-harvest condition including wear, damage, modifications and treatments, and trade standards for thickness.
To learn more about GIA’s pearl reports and services, visit https://www.gia.edu/gem-lab-service/pearl.
