Pre-Auction Analysis: November 10th 2021, Sotheby’s Geneva, Magnificent Jewels and Noble Jewels

As some parts of the industry have been prevented from traveling to Geneva 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 9 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: 205

Description: 9.22 ct Fancy Intense Yellow, Radiant, VVS1 (may be internally flawless after minor repolishing) and 9.34 Fancy Intense Yellow, Radiant, VS2

High Auction Estimation: $11,735 pc

Price realized: $20,761 pc

Rarity for both diamonds: A small number of similar diamonds enter the market yearly… Check Rarity Here 

GIA Report for 9.22 ct: View

GIA Report for 9.34 ct: View

Analysis: A pair of Fancy Intense Yellow Radiant cut diamonds mounted in yellow gold, while perfectly casing the girdle area and the lower part of the pavilion. Looking at the facet alignment of the pavilion, the lower depth and the large table, it is reasonable to assume that both stones were polished from what used to be a Round Brilliant cut, in order to reinforce the color. The VS2 clarity grade was given to the 9.34 carat due to a black crystal in the center of the table. Both stones look larger than most fancy color diamonds in this weight.

Visual Assets:

Total Average Score 10 out of 12

Lot: 276

Description: 3.27 ct Fancy Intense Yellow, Round, VVS1 (may be internally flawless after minor repolishing) and 3.37 ct Fancy Intense Yellow, Round, VVS1

High Auction Estimation: $22,965 pc

Price realized: $25,987 pc

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

GIA Report for 3.27 ct: View

GIA Report for 3.37 ct: View

Analysis: Two Fancy Intense Yellow Round Brilliant cut diamonds mounted in yellow gold. Looking at the table size, depth and open culet we can assume that these two stones were cut and polished between the 1960’s to the late 1970’s. The inner-grade seems to be average and no significant Green or Brown undertone is present in the Yellow hue. 

 Visual Assets:

Total Average Score 9 out of 12

Lot: 288

Description: 43.35 ct, Fancy Vivid Yellow, Radiant, VS2

High Auction Estimation: $52,732 pc

Price realized: $52,248 pc

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

GIA Report: View

Analysis: A very large Fancy Vivid Yellow Emerald cut diamond. The inner-grade is above average, and the color dispersion is average for an Emerald cut, not leaving too many colorless areas on the face up view. No Green or Brown undertone is visible in the hue.

*Please refer to lot 71 at the Christie’s auction

Visual Assets:

Total Visual Score 9 out of 12

Lot: 232

Description: 2.27 ct Fancy Orangy-Pink, Heart, VS2

High Auction Estimation: $91,145 pc

Price realized: $90,939

GIA Report: View

Analysis: A Fancy Orangy-Pink Heart shape with high inner-grade, and some colorless areas in the crown. The overall color is “warm” and meets our expectations from a stone with ~20% Orange and 80% Pink. The stone’s face up view corresponds to its weight.

Visual Assets:

Total Visual Score 10 out of 12

Lot: 281

Description: 3.88 ct Fancy Vivid Orangy-Yellow, Round, VS2

High Auction Estimation: $106,622 pc

Price realized: $113,288 pc

GIA Report: View

Analysis: A Round Brilliant cut diamond with ~20% Orange and ~ 80% Yellow. The stone has the highest possible inner-grade. As for the color dispersion, we clearly see many black reflections on the face up view, caused by a shallow angle of the pavilion. Looking at the characteristics of the black scattered inclusions in combination with the high saturation, we can assume the stone originated from the Zimmi area in Sierra Leone. Examining the diamond sideways on a white background, we could see a dark tint in the girdle area, a typical color characteristic for Yellow fancy color stones from that geographic area.

Visual Assets:

Total Visual Score 10+ out of 12

Lot: 292

Description: 25.63 ct, Fancy Orangy-Pink, Radiant, VS2

High Auction Estimation: $228,567 pc

Withdrawn from auction

GIA Report: View

Analysis: A very large Fancy Orangy-Pink Radiant cut diamond with a low inner-grade and high color dispersion, leaving very few colorless patches on the face up view. There was a moment of doubt when we thought we were looking at a straight Pink diamond, as the Orange modifier is not very dominant. It seemed like the diamond crystal has a low translucency index, making the overall look slightly “Dull”. This could be an indication the stone is type IIa. 

Visual Assets:

Total Visual Score 10 out of 12

Lot: 233 

Description: 3.53 ct Fancy Vivid Yellow, Pear, VS1

High Auction Estimation: $250,367 Total

Price realized: $371,533 Total

Rarity: A small number of similar diamonds enter the market yearly… Check Rarity Here 

GIA Report: View

Analysis: A Vivid Yellow Pear shape with the highest possible inner-grade for a vivid Yellow. The proportions of the stone and the open culet indicates the stone was manufactured sometime in the 19th century. No Brown or Green undertone is present in the color mix and it exhibits a Yellow hue with a soft tint of Orange. Due to the extremely high crown and the odd proportions, color dispersion is not high, leaving certain areas with dark reflections. The open culet and the metal behind it are visible to the naked eye and the stone’s face up view looks smaller in relation to its carat weight. 

Visual Assets:

Total Visual Score 11 out of 12

Lot: 241 

Description: 4.53 ct, Fancy Intense Pink, Pear, VVS1

High Auction Estimation: $912,653 pc

Price realized: $806,335 pc

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

GIA Report: View

Analysis: A Pear-shaped diamond that was polished and cut as a colorless diamond, leaving most of the color in the pointy area. This is probably an indication of the early period in which the diamond was polished. The undertone is average for a Pink as well as the inner-grade. When looking carefully in the colorless area in the center of the stone, it is possible to see hazy areas in the crystal, a quality that corresponds with the graining lines noted on the GIA report.

Visual Assets:

Total Visual 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.