Sotheby’s Hong Kong Magnificent Jewels, October 7th, 2020
As most of the industry has been prevented from flying during this special period and inspect the lots physically, we believe this current analysis is even more relevant than ever.
Our Sotheby’s Hong-Kong Pre-Auction Analysis focuses on elements that are hidden from the unprofessional eye. We will describe the important visual elements for those who cannot attend the preview and discuss characteristics such as: Undertone, Color Dispersion, and Inner-Grade (UDI; a detailed explanation appears at the bottom of this article). When we analyze and grade any Fancy Color Diamond it is always done in relation to its GIA grade.
We use grades 1, 2, 3, and 4, 1 being the lowest grade. Grade + is granted in rare cases and stands for stones with an exceptional characteristic. Stones that receive a minimum total UDI score of 8, without a red remark, are considered to be “Gems” and are generally sought after by high-end jewelry brands, collectors and the investment community.
For your convenience, we have added direct links for the GIA reports.
- All images in this article review were taken with an iPhone 11pro, no filters were applied.
- All auction valuations are per carat and in US Dollars.
Lot #1753
1.95 carat Fancy Intense Blue, Round, VVS1
And
1.63 carat Fancy Intense Blue, Round, VS1
High catalog estimation: $1,261,565 per carat
Didn’t reach the minimum
The color characteristics for this “pair” of rounds are quite similar, but the cut and proportions are very different, a fact that impacts the premium this item should have received as a matching pair I.e. a very different table size (58% and 62%), depth and different crown angles.
1.95
Inner Grade |
Color Dispersion |
Undertone |
Quality Remark |
4 |
3 |
3 |
Low compatibility |
Click here to check the rarity of this stone
To review the GIA Report Click here
1.63
Inner Grade |
Color Dispersion |
Undertone |
Quality Remark |
3 |
3 |
3 |
Low compatibility |
Click here to check the rarity of this stone
To review the GIA Report Click here
Total Average Score: 9.5 out of 12
Lot #1756
4.84 carat, Fancy Vivid Blue, Pear, IF. High catalog estimation: $1,732,813 per carat
Withdrawn from auction
Click here to check the rarity of this stone

A rare, Blue Vivid pear shape, with poor dispersion as a result of a
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