This Sotheby’s Hong Kong pre-auction analysis focuses on visual elements that are not expressed on the GIA report, such as Undertone, Color Dispersion, and Inner-Grade (UDI). We use grades such as 1, 2, 3, and 4 to describe these features. The grade 4+ is used in special cases to describe unusual visual characteristics.
This large Vivid Yellow Emerald cut was manufactured like a colorless diamond. Hence, we assume that it was not manufactured in the last two or three decades.
According to our Rarity Evaluator, a stone with these gemological characteristics comes to the market once every few years and receives the “one of a kind” grade
According to our Rarity Evaluator this rare diamond receives a “One of-a-kind” grade. New pink (or purple pink) diamonds in the intense grade above 5 carat come into the market once every few years. Internally flawless pink diamonds represent 7% of all pink diamonds
This 5.03 carat Fancy Vivid Green diamond is one of the largest Vivid Green diamonds seen at auction in recent years. Though the GIA generally employs softer grading criteria when determining a stone’s intensity level, this Vivid Green diamond exhibits a relatively high inner grade (grade 3).
Noticeable discrepancies between live and in person auction house diamonds can create a bit of controversy. When a customer buys a high quality, fairly priced stone in retail and later sees what appears to be a comparable stone in an auction catalogue for a significantly lower price, it disappoints the owner.
This Vivid Pink has quite a low inner-grade (grade 2). The undertone is warm, leaning towards the orange spectrum (grade 2). The color dispersion is very high and earned a grade of 4. The GIA photograph in the Sotheby’s catalogue is the most accurate reference for this stone’s undertone (p 358-359).
It is very rare to see a diamond with a 1:54 ratio and low depth percentage of 59.9%, which should be considered a feature, as it makes the diamond appear larger than its actual size. The color is very dark and could easily be mistaken a Deep Blue.