Pre-Auction Analysis: April 20th, 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.

The diamonds in this analysis were photographed, as always, in the viewing hall of the auction house; this is the first time they have been photographed under LED lights. Please note that most diamonds appear less saturated in real life.

Lot #1759

7.0 carats, Fancy Intense Purplish Pink, Emerald, IF

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

High catalog estimation: $1,010,279 per carat

Didn’t reach the minimum

An unusual shallow and elongated Pink Fancy Color Emerald cut. The amount of purple creates a desirable hue, and the color will probably meet the expectations of most buyers who are looking to own a Pink diamond with a strong intense Inner-Grade. 

Cutting and polishing a perfect Emerald cut poses many challenges during the manufacturing process. It is rare to see a perfect one, and it will receive a significant premium over other shapes if all else is equal. However, In this case, the 46% depth and the 1.64 length/width ratio creates a noticeably large colorless area, spanning across 70% of the faceup view and spoils the overall appearance. 

The fact the stone’s weight is exactly 7.00 carat, could bother some professional buyers, being that the stone is internally flawless and might need to go through a re-cut procedure if pulled out of the ring. Re-polishing this diamond might result, risking the loss of the  7 carat weight, changing its weight prifix to 6.              

Visual Assets

Total Visual Score 9 out of 12

To review the GIA Report of 7.00 ct, F.I.P/P, EM, IF Click here 

Lot #1743

23.48 carats, Fancy Deep Pinkish Orange, Pear, Cartier

*Further accompanied by a GIA letter stating that this is the largest Fancy Deep Pinkish Orange, Natural Colour diamond that they have graded as of the date of this letter. Accompanied by Cartier Certificate of Authenticity.

High catalog estimation: $265,573 per carat

Didn’t reach the minimum

A very large Fancy Deep Pinkish Orange pear-shape with a color-only GIA report. A pinkish orange color combination indicates that the orange hue constitutes about 75% of the color mix. The clarity falls under the I1 clarity grade as there are several large feathers around the stone reflecting under the table. The undertone is lacking any brown and as such meets the expectations of the color description in the report. The stone has no fluorescent and the Color distribution is high.

Visual Assets

Total Visual Score N/A

To review the GIA Report of 23.48 cT, F.D. P/O, PS Click here 

Lot #1742

43.35 carats, Fancy Vivid Yellow, Emerald, VS2 

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

High catalog estimation: $71,184 per carat

Didn’t reach the minimum

A large vivid yellow Emerald cut with average visual assets. Color dispersion is above average for a step cut and there is no green or brown undertone in the color.

Visual Assets

Total Visual Score 10 out of 12

To review the GIA Report of 43.35 ct, F.V.Y, EM, VS2 Click here 

Lot #1761

3.63 carats, Fancy Vivid Purple-Pink, Radiant

High catalog estimation: $672,993 per carat

Didn’t reach the minimum

A vivid purple pink with an attractive undertone and a solid vivid Inner-Grade. The stone is accompanied by a “color only” report probably due to the fact that it has a very low clarity grade. The blemishes are visible to the naked eye.

Visual Assets

Total Visual Score 10 out of 12

To review the GIA Report of 3.63 ct, F.V.P/Pink, Rad Click here 

Lot #1693

5.05 carats, Fancy Intense Purplish Pink, Cushion, SI2

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

High catalog estimation: $407, 360 per carat

Price realized: $343,962

A quite large intense purplish pink cushion shape with average color dispersion, inner-grade and undertone. The SI2 includes an open cavity on the table and the rest of the blemishes are visible to the naked eye. 

Visual Assets

Total Visual Score 9 out of 12

To review the GIA Report of 5.05 ct, F.I.P/ P, CU, SI2 Click here 

Lot #1760

1.93 carats, Fancy Vivid Blue, Heart

High catalog estimation: $666,158 per carat

Didn’t reach the minimum

A shallow Fancy vivid blue heart-shape with 38.9% depth. The “vivid” inner-grade is strong, the color is dispersed perfectly around the face up view and only a small amount of gray undertone is present in the hue. The low depth percentage makes the diamond appear much larger than its actual weight. 

The stone has a color only report, probably because the owner wanted to downplay the low clarity grade as the blemishes are visible to the naked eye. 

Visual Assets

Total Visual Score 11 out of 12

To review the GIA Report of 1.93 ct. F.V.B. HS Click here 

Lot #1679

3.08 carats, Fancy Pink, Radiant, VS1

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

High catalog estimation: $334,345 per carat

Didn’t reach the minimum

A rectangular Fancy pink radiant cut with a pleasant undertone. The Inner-Grade is questionable as the stone sits in a closed pink gold basket. Surrounding the 70% table are large dark colorless areas situated on the crown. Although the stone is rectangular it has a low depth percentage of 60% 

Visual Assets

Total Visual Score N/A out of 12

To review the GIA Report of 3.08 ct, F.P, Rad, VS1 Click here 

Lot #1677

8.88 carats, Fancy Vivid Yellow, Emerald, VVS2

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

High catalog estimation: $123,058 per carat

Price realized: $125,403

A vivid yellow Emerald cut with a strong vivid inner-grade and an emblematic carat weight of 8.88 that symbolizes prosperity and success in the chinese culture.The angle alignment of the facets corresponds to a colorless diamond with lacking the intention to concentrate color. As such, the dispersion is low, revealing many colorless areas on the face up view. 

Visual Assets

Total Visual Score 10 out of 12

To review the GIA Report of 8.88 ct, F.V.Y, EM, VVS2 Click here 

Lot #1741

0.81 carats, Fancy Deep Pink, Round and

0.79 carats Fancy Deep Pink, Round, SI2 

High catalog estimation: $321,396 per carat

Price realized: $283,983

Two fancy deep pink round brilliant diamonds set in an open gold mounting. Each stone is polished in a different manner and the compatibility is low. One stone received the SI2 clarity grade and the other, with a visible crystal under the table, has a “color only” report, probably in order to downplay the lower clarity grade.

Visual Assets

To review the GIA Report of 0.81 ct, F.D.P, RS Click here 

To review the GIA Report of 0.79 ct, F.D.P, RS, SI2 Click here 

Total Average Score 8 out of 12

Lot #1731

7.31 carats, Fancy Vivid Yellow, Round, SI1

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

High catalog estimation: $35,172 per carat

Didn’t reach the minimum

A vivid Yellow Round brilliant cut diamond polished in an antique style it can be assumed that the stone was manufactured early in the last century. The symmetry is “Fair,” the depth percentage is 65 and the color dispersion is low. These are common features in early produced round diamonds. The SI1 is eye-clean and the inner-grade is low, bordering on  a fancy intense yellow.

Visual Assets

Total Visual Score 5 out of 12

To review the GIA Report of 7.31 ct, F.V.Y, RS, SI1 Click here 

Lot #1708

0.64 carats, Fancy Vivid Purplish Pink, Marquize, VS2

High catalog estimation: $381,701 per carat

Didn’t reach the minimum

A vivid purplish pink Marquize with exceptional visual assets. The GIA report is dated 2012

Visual Assets

Total Visual Score 12 out of 12

To review the GIA Report of 0.64 ct, F.V.P/P, MQ, VS2 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.