Pre-Auction Analysis: Sotheby’s Hong-Kong October 3rd 2017
This pre-auction analysis will focus on visual elements and other observations that are not expressed on the GIA report nor in the catalog processing the images. Our analysis expresses characteristics such as Undertone, Color Dispersion, and Inner-Grade (UDI). We use grades 1, 2, 3, and 4 (1 standing for the lowest grade). The grade 4+ is quite rare and stands for an exceptional characteristic. Stones that are above the SI2 clarity grade and with a total UDI quality score of 8 or above are considered to be gems and are probably suitable for high-end jewelry, collectors, and the investment community.
All images in this review were taken with an iPhone 7.
All auction valuations are per carat and in US Dollars.
Important note: We strongly recommend downloading the beta version of the new FCRF app and using the auction calculator. This app lets you calculate your bidding price (per carat), including the house commission, as you follow the lot.
Lot # 1673
2.03 carat fancy vivid purplish pink Kite step cut, I2
High catalog estimation: $1,220,000 per carat
Price Realized: $500,000 per carat
Any 2-carat pink in the vivid category is considered rare and in-demand. However, this diamond has two caveats that should be taken into account. The first one would be the I2 clarity grade. In addition, the indented natural on the table is visible to the naked eye, which for some reason cannot be seen on the catalog. The second caveat would be its odd shape that is not favored by jewelry designers nor traditional diamond buyers.
The inner-grade is above average and receives the grade 3.
The color dispersion is low, with a large colorless area in the table, and receives the
grade 2.
The pink undertone is quite “sweet” due to the purple color in the mix and receives the grade 3.
Total quality score: 8 (I2 clarity)
Lot’ 1864
5.14 carat fancy deep blue Pear shape, SI1
High catalog estimation: $1,865,000 per carat
Not Sold
In the last couple of years, most important blue fancy color diamonds seen on the marketplace are pre-owned. Most of them also went through a re-cut procedure to improve their color grade. The reason for that is that no new blue fancy color rough has been reported found by the major mining companies in the last few years. According to the FCRF Rarity Evaluator, a stone like this will be unearthed only once every 10–13 years.
This rare, deep blue pear shape has a rounded point and an open culet and was cut as a classic white diamond (although the GIA report states it is a modified pear shape for an unknown reason). These indicators imply that the stone was originally cut a few decades before the issue date of its GIA report.
The diamond’s general appearance is actually better in real life in comparison to the catalog image, which usually isn’t the case.
A high inner-grade is inherent in fancy color diamonds that are graded deep, and as such, it automatically receives the grade 4.
due to the fact that it was cut as a colorless diamond, the color dispersion is quite low and exhibits a large, lighter area in the center of the stone and receives the grade 2, Having said that, in this case it dilutes the general darkness of color and gives it a pleasant look.
The blue undertone is quite good and appears to be better than most deep blue fancy color diamonds and receives the grade 3.
Total quality score: 9
Lot’ 1685
2.86 carat fancy vivid purplish pink Cushion cut, I2
High catalog estimation: $1,000,000 per carat
Price Realized: $1,100,000 per carat
This vivid purplish pink cushion cut has many characteristics that grant it a premium; however, most savvy buyers might feel uncomfortable with a color-only report, a factor one cannot overlook. Regardless, it is important to note that the inclusions are not visible to the naked eye and that the stone is “Eye-clean.”
The inner-grade of this 2.86 is above average and receives the grade 3.
The color dispersion doesn’t match the processed and perfect catalog image. The colorless patches in the crown area grant the stone the grade 3.
Thanks to the significant purple present in the color mix, the undertone of this diamond will meet most color expectations from a pink diamond by most buyers and receives the grade 4.
Total quality score: 10 (color-only report)
Lot’ 1698
20.03 carat fancy vivid yellow Emerald cut, IF
High catalog estimation: $1,240,000 per carat
Price Realized: $2,100,000 per carat
A large elongated vivid yellow Emerald cut diamond with a 1.37 (length–width) ratio.
The inner-grade is quite strong and receives the grade 3.
In sharp contrast to the catalog image, it has significant colorless patches and receives the grade 3.
The stone exhibits no significant green or brown undertone and receives the grade 3 as well.
Total quality score: 9
Lot’ 1852
5.21 and 5.01 carat fancy pink Pear shape diamond pair, IF, VS1
High catalog estimation: $500,000 per carat
Not Sold
Two matching stones with similar visual characteristics and similar measurements. Other than the fair symmetry on the 5.01, they exhibit a good match in a pair of earrings. According to the FCRF Rarity Evaluator, only three stones with similar characteristics will come into the market every year. Finding a matching pair is exponentially rarer.
The inner-grade is below average and receives the grade 2.
Although there is a slight difference in the undertone between the two stones, they both demonstrate an undertone which is above the average fancy pink and receive the grade 3.
The color dispersion is quite low, with many colorless patches, and receives the grade 2.
Total quality score: 7
Lot’ 1853
11.46 carat fancy vivid yellow Oval shape, VVS1
High catalog estimation: $100,000 per carat
Price Realized: Per Carat- $88,000
The inner-grade of this vivid yellow oval is above average and receives the grade 3.
In sharp contrast to the impeccable catalog picture, the stone has colorless patches and receives the color dispersion grade 3.
The undertone exhibits a yellow color with no green or brown influences and receives the grade 4.
According to the FCRF Rarity Evaluator, only three to seven new stones with similar characteristics come into the market every year.
Total quality score: 10
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