Pre-Auction Analysis: May 11th, Sotheby’s Geneva, Magnificent Jewels and Noble Jewels

As most of the industry has been prevented from traveling during this challenging period, this Auction Analysis could help those who would like to bid without physically inspecting the goods.                                                 

Our Sotheby’s Geneva 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). We analyze and grade Fancy Color Diamonds relative to their 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, pass the industry threshold and can be traded easily. Fancy Color Diamonds that are graded 10 or above, (without a quality remark) are usually 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 12 mini, no filters were applied.
• All auction valuations are per carat and in US Dollars.

Sotheby’s, Geneva, Magnificent Jewels and Noble Jewels: Part I, May 11th 2021 

Lot #160

1.61 carats, Fancy Vivid Blue, Oval, VS2

A similar diamond enters the market once every… Check Rarity Here

High catalog estimation: $1,224,286 per carat

Price realized: $963,416 pc

Looking at the cut and polish of the stone, it is quite obvious the stone was manufactured before the 1990’s. The color dispersion is low, the depth percentage is 72% and the gray undertone is quite prominent.

Visual Assets

Total Visual Score 7 out of 12

To review the GIA Report of 1.61ct, FVB, OV, VS2 Click here

Lot #157

3.11 carats, Fancy Deep Blue, Pear, VS2 

A similar diamond enters the market once every… Check Rarity Here

High catalog estimation: $985,783 per carat

Price realized: $690,967 pc

A very dark looking Fancy Deep Blue pear shape with an insignificant amount of Gray Undertone and 73% depth. 

Visual Assets

Total Visual Score N/A

To review the GIA Report of 3.11ct, FDB, PS, VS2 Click here 

Lot 156

5.04 carats, Fancy Vivid Orangy Pink, Pear, VS2

High catalog estimation: $782,767 per carat

Price realized: $505,648 pc

Orangy Pink Fancy Color Diamonds are typically warmer in color than single color pink diamonds. As such, the vivid saturation in this hue combination is quite rare. The color dispersion is high with very few colorless patches and the undertone meets the expectations from the GIA color description. The depth percentage is relatively low. 

Visual Assets

Total Visual Score 9 out of 12

To review the GIA Report of 5.04ct, FVO/P, PS, VS2 Click here

Lot #140

1.93 carats, Fancy Vivid Bluish Green, Radiant, I1 

High catalog estimation: $538,886 per carat

Didn’t reach the minimum

A rare color combination especially in this large carat size. The I1 clarity is peripheral and not very visible to the naked eye. The very high crown is the main contributor to the high depth percentage (80%) that has an impact on the color dispersion as well.   

Visual Assets

Total Visual Score 10 out of 12

To review the GIA Report of 1.93ct, FVB/G Rad, I1 Click here 

Lot #142

6.05 carats, Fancy Pink, Radiant, IF

A similar diamond enters the market once every… Check Rarity Here

High catalog estimation: $409,123 per carat

Price realized: $245,506 pc

An elongated (1.5 width to length ratio) Fancy Pink Diamond with a warm undertone and noticeable colorless areas in the crown. The inner-grade is above the average.

Visual Assets

Total Visual Score 7 out of 12

To review the GIA Report of 6.05ct, FP, Rad, IF Click here 

Lot #158

18.38 carats, Fancy Vivid Yellow, Pear, VS2

A similar diamond enters the market once every… Check Rarity Here

High catalog estimation: $190,746 per carat

Price realized: $153,107 pc

A large Fancy vivid yellow pear shape diamond with high visual assets. The inner-grade is above average and no green or brown undertone is present in the color mix. There are some colorless areas in the rounded area of the crown. 

Visual Assets

Total Visual Score 11 out of 12

To review the GIA Report of 18.38ct, FVY, PS, VS2 Click here

Lot #141

1.51 carats, Fancy Deep Purple-Pink, Radiant, SI2 

A similar diamond enters the market once every… Check Rarity Here

High catalog estimation: $138,455 per carat

Didn’t reach the minimum

A stone with 40% purple and 60% pink. The SI2 clarity is located under the table and is not very visible to the naked eye due to the fact it blends into the dark color of the stone. The color dispersion is very high with no colorless patches. A subtle gray undertone is present in the hue, a typical quality for stones with a purple color modifier.

Visual Assets

Total Visual Score 11 out of 12

To review the GIA Report of 1.51ct, FDP/P, Rad, SI2 Click here 

General

We use 1, 2, 3, 4, and 4+ to grade the three visual elements that GIA is silent about, although they impact the value dramatically.

Inner-Grade refers to the strength of color within each GIA saturation category:

Grade 1 weakest, bordering the saturation below.

Grade 2 weak (most common).

Grade 3 full-bodied color (above average).

Grade 4 very strong saturation.

Grade 4+ applies to the vivid category only, exhibiting the strongest possible saturation (rarely seen).

Undertone refers to a subtle hue influence in the body color of the stone.

For example:

A Fancy Blue Diamond with a significant gray presence in its general appearance will be graded with a low undertone grade of 1. A Fancy Blue that has no gray influence that is close to a primary blue will receive the grade, 4.

In a Pink Fancy Color Diamond, a stone with a warm undertone (such as orange or brown) will receive a low undertone grade. A pink stone with a cold undertone (such as purple) will receive a high grade.

In Yellow Fancy Color Diamonds, low foreign influence or a light orange influence will grant the stone a high undertone grade. When the yellow undertone looks like a true primary yellow, it will receive the rare grade 4+. Green and brown undertones will grant a low grade in the yellow category.

Color Dispersion relates to how well the color is dispersed in the face-up view of a Fancy Color Diamond, regardless as to whether the GIA grades the stone as even. A stone with many colorless areas will receive the grade 1, while a stone that exhibits its face-up view with no colorless patches will receive the grade 4+. Unlike the first two elements, the color dispersion is not a gemological quality and is the result of cutter proficiency.