Dealers marketing the unique appearance of these diamonds have long contended that their stones are unduly penalized by the application of modern cut-grade criteria. They ensure that these diamonds are not judged by standards that they were never fashioned to meet, and from which they would likely receive a “Fair” or “Poor” cut grade. These parameters are derived from historical definitions of the old European cutting style, staff observations, and discussions with trade professionals. Lower half facet length: less than or equal to 60 percent.Crown angle: greater than or equal to 40 degrees.Table size: less than or equal to 53 percent.GIA identifies classic old European cuts using these criteria: As a result, GIA does not apply a cut grade to diamonds cut in the old European style. Its appearance is associated with a time that predates expectations of conformity with the appearance of the modern-day round brilliant. This accommodated the distinctive proportions of diamonds cut in this classic style. Initially, GIA allowed only one exception-the old European cut-into its cut-grading system. This illustration shows the facet arrangement of an old European brilliant cut. There are five grades: Excellent, Very Good, Good, Fair, and Poor. The system’s grades are based on modern-day conventions and assess the proportions that yield the best combination of brightness, fire, scintillation, and pattern. GIA designed the system to assess the design quality and craftsmanship of diamonds cut in the standard round brilliant style when compared to modern preferences. The system was the culmination of years of research that included the results of preference testing among a wide variety of groups, including trade professionals and consumers. The name “unmodified round brilliant” was applied to a symmetrical round cut with a regular array of 58 facets, cut to modern standards. In 2005, GIA introduced a cut-grading system for unmodified round brilliant cut diamonds. The GIA Cut-Grading System for Unmodified Brilliant-Cut Diamonds This article explains GIA’s approach to describing these beautiful older-style brilliant-cut diamonds. Recent high prices for precious metals have caused many pieces containing older-style diamonds to be broken up, releasing more of these beautiful gems into the market and increasing appreciation for their historic nature. Because some served as transitions between older and more-modern styles, some trade professionals call them “transitional cuts.”

Many older round brilliants were cut between the 1870s and the 1940s.

A modern brilliant can display a tighter mosaic of light and dark that might be described as “splintery” by those who prefer older cutting styles. Digitally modified image by Al Gilbertson, © GIA, courtesy of Michael GoldsteinĬompared to a modern brilliant, older gems typically show larger face-up patterns of light and dark-what might be described as a “checkerboard” or “blocky” pattern. brilliant has a much smaller table (38.5 percent), a higher crown, shorter lower halves, and a much larger culet. Applied Jewelry Professional ™ Online DiplomaĬompared to a modern round brilliant cut, this older-style 1.07-ct.

Brilliance definition