Pre-Auction Analysis: November 26th 2019, Christie’s Hong Kong, Magnificent Jewels

Our Christie’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). When we analyze and grade any Fancy Color Diamond it is always done in relation to its 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, are considered to be “Gems” and are generally 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 11pro, no filters were applied.
• All auction valuations are per carat and in US Dollars.

Lot # 2054

3.24 carat Fancy Vivid Blue, Emerald cut, IF. MOUSSAIEFF. High catalog estimation: $2,375,542 per carat

Price realized: $2,118,268 pc

Prevalence: Enters the market every 3 to 7 years

A square Emerald cut with a solid inner-Grade, average color dispersion and undertone. The amount of gray undertone in the hue is small and the overall color experience could probably meet most people expectations from a blue diamond.

Total Visual Score: 9 out of 12 

To review the GIA Report Click here -> 12625281

Lot # 1966

2.76 carat Fancy Intense Purple-Pink, Pear cut, VVS1, High catalog estimation: $697,170 per carat

Price realized: $444,569 pc

Prevalence: 1-2 new similar diamonds enter the market per year

The color inner-grade on this pink PS is low for the intense category, alongside a purple modifier which creates an overall pleasant undertone. There are some colorless patches in the crown area and next to the culet.

Total Visual Score:   8 out of 12 

To review the GIA Report Click here -> 2195146853

Lot # 2046

8.75 carat Fancy Vivid Yellow, Cushion cut, VVS2.

8.07 carat Fancy Vivid Yellow , Cushion cut, VVS1. 

High catalog estimation: $91,519 per carat

Price realized: $68,403 pc

Prevalence for a single stone: 5-10 new similar diamonds enter the market per year

A highly unusual pair of vivid yellow cushion-cut diamonds. These two large stones were cut and polished as regular colorless diamonds and as a result, didn’t reach their full color potential. 

Due to the facet alignment, the color dispersion is low, while most of it is concentrated in the table area, resulting in a yellow “ring” around the culet. The rest of the face-up view receives some yellow reflections from the center. A subtle green undertone is present in the color as well. 

8.75 and 8.07

8.75 To review the GIA Report Click here -> 2205045361

8.07 To review the GIA Report Click here -> 1206030521

Total Visual Score: 7  out of 12

Lot # 2034

10.23 carat Fancy Vivid Yellow, Radiant cut, VVS2, HARRY WINSTON. High catalog estimation: $62,697 per carat

Price realized: $49,519 pc

Prevalence: 4-8 new similar diamonds enter the market per year

A relatively large, fancy vivid yellow radiant-cut diamond. Looking closely at the facet alignment on the pavilion, it is evident that the stone was polished from what used to be a round or a cushion brilliant cut, a procedure done in order to reinforce the color and upgrade the saturation grade. This procedure usually results in a distinct colorless pattern on the face up view of the stone.

Total Visual Score:  9 out of 12

To review the GIA Report Click here -> 11370121

Lot # 1975

21.57 carat Fancy Yellow, Radiant cut, VS2. High catalog estimation: $20,814 per carat

Result: Didn’t reach the minimum

Prevalence: 2-3 new similar diamonds enter the market per year

A large, fancy yellow radiant-cut diamond with a solid inner-grade, average color dispersion, with some colorless areas in the crown and average undertone.

Total Visual Score:  9 out of 12

To review the GIA Report Click here -> 16226775

Lot # 1976

12.41 carat Fancy 12.41 carat Fancy Yellow, Radiant cut, VS1.

Prevalence: 3-5 new similar diamonds enter the market per year

and

12.15 carat Fancy Yellow, Radiant cut, VVS1.

Prevalence: 1-2 new similar diamonds enter the market per year

High catalog estimation: $18,280 per carat

Price realized: $18,127 pc

Two fancy yellow radiant-cut diamonds with different undertone. In addition, one was polished directly from rough and the other is a re-polish from what used to be a round or a cushion-brilliant cut. Overall, they are of low compatibility as a matching pair. 

12.41 

To review the GIA Report Click here -> 13779336

12.15

To review the GIA Report Click here -> 11592214

Total Visual Score:  8 out of 12

Lot # 1964

9.00 carat Fancy Intense Yellow, Pear shape, SI2. High catalog estimation: $21,379 per carat

Result: Didn’t reach the minimum

Prevalence: Enters the market once every 1-2 years 

A large fancy intense yellow pear shape with a strong inner-grade, bordering to a vivid. The SI2 clarity is located in the center of the stone and is visible to the naked eye. The effect of the strong blue fluorescence is noticeable under a direct sunlight. 

Total Visual Score:  10 out of 12

To review the GIA Report Click here -> 5141672208

Lot # 1962

4.15 carat Fancy Vivid Yellow, Marquise cut, VS1. High catalog estimation: $46,366 per carat

Result: Didn’t reach the minimum

A vivid, yellow Marquis with an absolute yellow hue with no brown or green undertone in the color. The color dispersion is low, leaving a large colorless area in the center.

Total Visual Score:  9 out of 12

To review the GIA Report Click here -> 6203332136

Lot # 1960

3.60 carat Fancy Vivid Orange-Yellow, Pear cut. High catalog estimation: $42,759 per carat

Result: Didn’t reach the minimum

An orange-looking, fancy color diamond with approximately 40% orange color modifier and 60% yellow. The stone has a large, indented natural/feather under the left prong, which is visible to the naked eye. 

Total Visual Score: 12  out of 12

To review the GIA Report Click here -> 1196971866

General

We use 1, 2, 3, 4, and 4+ to grade the three visual elements that GIA is silent about, however 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 abounded).

Grade 3 full-bodied color (above average).

Grade 4 very strong saturation.

Grade 4+ applies for 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 and will be 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 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 has only to do with cutter proficiency.