Pre-Auction Analysis: October 12th, 2021 Sotheby’s Hong Kong, Magnificent Jewels

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

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). 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: 1868

Description: 74.49 ct, Fancy Vivid Yellow, Cushion, IF

High Auction Estimation: $43,112 pc

Didn’t reach the minimum

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

GIA Report: View

Analysis:  A very large, Vivid Yellow Cushion cut diamond. From the small table (57%) the large, colorless crown that is surrounding it, and the facet alignment on the pavilion, it is reasonable to assume that this diamond is a result of a recut, from what used to be an old-mine cushion, with a lower saturation. In this case, the desire to maintain the maximum weight outweighed the motivation to produce a modern cut, with a proper color dispersion; the large, colorless areas on the crown are a typical example. The vivid Inner-Grade is average and an insignificant undertone is present in the color.

Visual Assets:

Total Visual Score 8 out of 12

Lot: 1865

Description: 1.02ct, Light Pink, Cushion, VS2 and 1.01ct, Fancy Light Greenish Blue, Cushion, SI1

High Auction Estimation: $64,195 Total

Price realized: $56,672 Total

Rarity (Only for the pink): An extremely small number of similar diamonds enter the market yearly… Check Rarity Here 

GIA Report for 1.02ct, Light Pink: View

GIA Report for1.01ct, Fancy Light Greenish Blue: View

Analysis: A ”Toi et Moi” (you and me) ring with two complementary colors, surrounded by pink melee.

In cases when two Fancy Color Diamonds are arranged in one piece of jewelry, it is customary to match the saturation levels. In this case, the seller chose to place a Light Pink with a Fancy Light Greenish Blue which reduces the compatibility of this pair.  Since the saturation is very weak by definition and the pink gold is completely covering both stones, we are unable to grade the three visual parameters.

Visual Assets:

Lot: 1824

Description: 8.02ct, Fancy Vivid Yellow, Emerald, VS2

High Auction Estimation: $80,045 pc

Price realized: $64,608 pc

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

GIA Report: View

Analysis: A highly saturated Vivid Yellow Emerald cut diamond, with a standard color dispersion for an elongated emerald, and an insignificant undertone in the color. Overall, this Vivid Yellow Emerald cut diamond grants the full “yellow experience” one would expect from a yellow Fancy Color ring. Due to the classic facet alignment of this elongated step cut, it is not expected to have a full dispersion of color covering the center of the stone.

Visual Assets:

Total Visual Score 10 out of 12

Lot: 1869

Description: 0.71ct, Fancy Vivid Green, Cushion, VVS2

High Auction Estimation: $218,265 Total

Didn’t reach the minimum

GIA Report: View

Analysis: A Vivid Green Cushion cut diamond with good visual parameters. The hue exhibits an absolute green hue with no significant yellow or gray undertone. The color dispersion is high, covering most of the face-up view of the stone. The inner-grade is solid and meets our expectations from a vivid saturation.

Visual Assets:

Total Visual Score 10 out of 12

Lot: 1839

(*price per carat of the 2.28 is calculated after deducting the approximate price per carat of the D IF 2.10 from the total estimation)

Description: 2.28ct, Fancy Pinkish Orange, Pear, IF

High Auction Estimation: $137,202 pc

Didn’t reach the minimum

GIA Report: View

Analysis: As opposed to stones with a Pink body color and an Orange modifier i.e. Orangy Pink, diamonds that have an Orange body color and a Pink modifier, like we see in this case, are extremely rare. Visually, to the untrained eye, both color combinations in most cases may look quite similar; however, savvy collectors who look to purchase this rare color blend may pay a high price when the stone leans towards a soft “peach” color. When a Pinkish Orange diamond looks similar to an Orangy-Pink, the premium in value will not be significant.

The Inner-Grade of this 2.28 is strong, the color dispersion is average, with a few colorless patches on each side of the stone and the undertone is quite warm.

Visual Assets:

Total Visual Score 9 out of 12

Lot: 1870

Description: 1.01ct, Fancy Vivid Pink, Heart, SI2

High Auction Estimation: $462,206 Total

Didn’t reach the minimum

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

GIA Report: View

Analysis: A 1.01 Vivid Pink, with strong blue fluorescence and an SI2 clarity. Unlike other diamond shapes, the heart shape is taken from the figurative content and needs to remain true to the classic outline to achieve the value of other diamond shapes. In this case, the shape of the heart is deformed, unsymmetrical and seems to have been forced during the polishing process on the rough, to keep it over one carat. The undertone is pleasant and the inner-grade is high.

Visual Assets:

Total Visual Score 9 out of 12

Lot: 1882

Description: 5.29 ct, Fancy Intense Green, Pear, SI1

High Auction Estimation: $631,3669 pc

Price realized: $577,413 pc

GIA Report: View

Analysis: This 5.29 Fancy Intense Green has a solid Inner-Grade and includes a few colorless patches situated in the rounded area of the shape. We can see an insignificant Yellow undertone in the hue which softens the green chroma and gives it a “mint” color rather than the typical “grass green”. The proportions of the stone correspond with the weight.

Visual Assets:

Total Visual Score 10 out of 12

Lot: 1871 

Description: 3.01 ct Fancy Vivid Blue,Emerald, VS1

High Auction Estimation: $1,920,680 pc

Price realized: $1,495,188 pc

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

GIA Report: View

Analysis: A rectangular, Vivid Blue Emerald cut diamond with a dark tone of color. Although the color in the picture and video seems to be even across the face up view, it is merely concentrated at the four corners of the pavilion. The rest of the colorless dark areas blend with the dark tone of blue and create an illusion of an even surface. The vivid inner-grade seems quite strong, however it draws its strength from the dark tone rather than the saturation.

Visual Assets:

Total Visual Score 9 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.