Pre-Auction Analysis: June 9th, 2021, Sotheby’s New York, Magnificent Jewels

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

Our Sotheby’s New York 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 pro, no filters were applied.
• All auction valuations are per carat and in US Dollars.

Lot #71 

25.03 carats, Fancy Intense Yellow, Cushion, VVS1

An extremely small number of similar diamonds enter the market yearly… Check Rarity Here

4.20 carats, Fancy Intense Yellow, Cushion, VS1

An extremely small number of similar diamonds enter the market yearly… Check Rarity Here 

*Additionally 89 cushion-cut Fancy Intense Yellow Diamonds weighing a total of 57.96 carats

High catalog estimation: $650,000 Total

Price realized:$564,500 Total

 * This lot was reported to be sold in the Sotheby’s auction in December 2020 for a total amount of $685,000, the high estimation in this sale is $650,000. 

The analysis will relate to the two center stones only.

A 25.03 Fancy Intense Yellow with a crown which is angled in a way that creates a noticeable colorless frame around the table. The 72% depth makes the stone look small relative to the diamond’s weight. The warm undertone is visible in the yellow hue.

The 4.20 carat has average visual assets and a Strong Blue Fluorescence

Visual Assets

To review the GIA Report of 25.03 ct, F.I.Y, CU, VVS1 Click here 

To review the GIA Report of 4.20 ct, F.I.Y, CU, VS1 Click here 

Total Average Score 8.5 out of 12

Lot #62

21.65 carats, Fancy Intense Yellow, Oval, VS2

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

High catalog estimation: $18,475 per carat

Price realized: $23,279 pc

A large Fancy Intense Yellow oval that was cut and polished like a colorless diamond with a low color dispersion. A typical facet alignment for Fancy Color Diamonds that were manufactured between the 1960’s through the early 1990’s. The Inner-Grade is solid and the yellow color has no undertone, creating an absolute yellow hue. 

Visual Assets

Total Visual Score 9 out of 12

To review the GIA Report of 21.65 ct, F.I.Y, OS, VS2 Click here 

Lot #34

7.16 carats, Fancy Yellow, Radiant, VVS1

An extremely small number of similar diamonds enter the market yearly… Check Rarity Here 

7.24 carats, Fancy Yellow, Radiant, VVS2 

An extremely small number of similar diamonds enter the market yearly… Check Rarity Here 

10.03 carats, Fancy Yellow, Radiant, VVS1 

An extremely small number of similar diamonds enter the market yearly… Check Rarity Here

High catalog estimation: $300,000 Total

Price realized: $378,000 Total

A series of three Fancy Yellow Radiant cut diamonds with average visual assets detailed in the chart below. Looking at the facet alignment, table size and the depth percentages we can assume these stones were re-cut from what used to be a Round Brilliant cut diamond with a lighter color.

Visual Assets

To review the GIA Report of 7.16 ct, F.Y, Rad, VVS1 Click here 

To review the GIA Report of7.24 ct, F.Y, Rad, VVS2 Click here 

To review the GIA Report of 10.03 ct, F.Y, Rad, VVS1 Click here 

Total Average Score 8 out of 12

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.