Our Sotheby’s Magnificent Jewels Pre-Auction Analysis focuses on elements that are not always visible to the untrained eye. We discuss characteristics such as Inner-Grade, Color Dispersion, and Undertone – collectively termed IDU. Professionals use the IDU method intuitively when analyzing a Fancy Color Diamond. The acronym we use makes these elements easier to remember.
Members who read this analysis should see it as a valuable supplement to the GIA report. A detailed explanation of the FCRF’s grading methodology can be found at the end of this article. We recommend reviewing it closely to broaden one’s professional vocabulary for describing fancy color diamonds to clients.
Focusing here is the Lot 28 and its’ analysis say; a remarkably large orange diamond featuring approximately a 40% brown modifier in its hue. This diamond exhibits exceptional visual qualities, characterized by a strong orange color sensation. According to the FCRF, True Face-Up tool, this radiant cut appears ~10% larger, a key attribute valued by jewelry buyers.
Another Lot 87, an elongated, vivid orange, oval-shaped diamond with I2 clarity, characterized by two large feathers extending along its shape. The diamond exhibits a bright color sensation, enhanced by its yellow fluorescence. In most cases, yellow fluorescence tends to impact the brightness of an orange diamond more positively than orange fluorescence.