Pre-Auction Analysis: October 7th 2019, Sotheby’s Hong Kong, Magnificent Jewels and Jadeite

This year’s sale takes place under a very challenging commercial climate. The civil riots in Hong Kong might reflect directly on the amount of people attending the sale and we recommend not overlooking this fact when we analyse the final results.

As always, Our 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 (IDU; a detailed explanation appears at the bottom of this article). When we analyse and grade of 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 IDU score of 8, without a red remark, are considered to be “Gems” and are generally sought after by high-end jewellery 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 10, no filters were applied.
• All auction valuations are per carat and in US Dollars.

Lot # 1820

10.64 carat Fancy Vivid Purplish Pink, Radiant cut, IF, Type IIa. High catalog estimation: $2,453,653 pc

Price Realized: $1,868,653 pc

According to the FCRF general rarity data, the majority of vivid pink diamonds on the market range from half a carat to one carat in size. According to the rarity calculator; a stone with these characteristics enters the market once every 25 years. Despite the fact that the stone is Type IIa (an attribute that benefits exclusively colorless diamonds), the pink undertone is pleasant, thanks to the purple modifier. The combination of a high crown and a 51% table (a small table for any square shape diamond) results in an average color dispersion, with two large colorless areas on both sides of the table. The Inner-Grade is below average in the vivid category

Total Visual Score:  8 out of 12 

To review the GIA Report Click here: 2195940932

Lot # 1819

9.71 carat, Fancy Intense Yellow, Brilliant cut, VS2. 

and

9.69 carat, Fancy Intense Yellow, Brilliant cut, VVS1.

High catalog estimation: $46,037 pc.

Result: Didn’t reach the minimum

Two fancy intense, yellow, round, brilliant cut diamonds, both with very large “table”; 70% and 68%, and a steep angled “crown”, creating a distinct color “ring” under the table, leaving many other colorless areas around the diamond’s face-up view.

The GIA graded the color distribution “Uneven” on both stones which corresponds to our low grade of color dispersion. The yellow color has no green or brown undertone and exhibits an attractive primary yellow hue, and the inner-grade is above quite high for an “Intense”.

9.71

 To review the GIA Report Click here: 5151025276

9.69

 To review the GIA Report Click here: 5151153107

 Total Average Score:  9 out of  12

Lot # 1795

16.01 carat Fancy Yellow, Cushion cut, VVS2. High catalog estimation: $14,344 pc

Result: Didn’t reach the minimum

A large, fancy intense, yellow with a GIA report dated 2007. In most cases the auction house updates older GIA reports, for some reason, they decided not to do so in this case.

The color dispersion is a border-line case between a grade 2 to a grade 3 and the inner-grade is below the average Intense grade.

According the FCRF rarity calculator, 1-2 new stones with these characteristics come into the market every year. 

Total Visual Score:  8 out of  12

To review the GIA Report Click here: 16385338

Lot # 1713

100.02 carat, Fancy Intense Yellow, Cushion cut, IF, Designed by Anna Hu. High catalog estimation: $53,782 pc

Price Realized: $57,847 pc

A very large, fancy intense, yellow Cushion-cut with visual elements that are above average. “Faint” fluorescents have no negative impact on the value of any yellow stone and the Internally Flawless clarity grade is always a “nice to have” feature.  

Total Visual Score:  9 out of 12

To review the GIA Report Click here: 6173064376

Lot # 1703

10.88 carat Fancy Vivid Yellow, Pear shape, VVS2. High catalog estimation: $91,977 pc

Result: Didn’t reach the minimum

Vivid yellow, pear shape diamonds that are cut as colorless “Pear Brilliant” diamonds, suffer from a low color dispersion which affects the general beauty of the stone. In this case, we assume the owner decided to prefer the symbolic ‘88’ weight ending, rather than the Inner-Grade and the overall aesthetic.   

Total Visual Score:  7 out of 12

To review the GIA Report Click here: 6203140924

Lot # 1699

5.18 carat Fancy Vivid Yellow, Emerald cut, VS1. High catalog estimation: $59,115 pc

Result: Didn’t reach the minimum

A vivid yellow, Emerald-cut diamond, with a solid inner-grade for a vivid and a relatively good color dispersion for a step cut diamond.

 Total Visual Score:  9 out of 12

To review the GIA Report Click here: 2195134749

Lot # 1698

3.01 carat Fancy Light Brownish Pink, Pear shape, SI1

2.01 carat Fancy Intense Yellowish Green, Cushion cut, VS1

1.05 carat Fancy Grey-Blue, Marquise shape, IF

1.01 carat Fancy Intense Orange-Yellow, Pear shape, SI1

0.62 carat Fancy Orangy Pink, Heart shape

0.25 carat Fancy Vivid Green-Yellow, Pear shape,SI1

0.25 carat Fancy Vivid Yellowish Orange, Pear shape, SI2

0.25 carat Fancy Intense Orangy Pink, Pear shape, SI2

High catalog estimation: $57,377 pc

Price Realized: $ 49,073 pc

A collection of Fancy Color Diamonds in various shapes and inconsistent qualities and price groups. Looking at the GIA issue dates (2007 through 2019), one can assume it is a bundle of random goods that were placed together recently. None of the above is a testimony of the quality  

3.01

To review the GIA Report Click here: 1217111622

2.01

To review the GIA Report Click here: 6222586992

1.05

To review the GIA Report Click here: 5172562754

1.01

To review the GIA Report Click here: 1318767978

0.62

To review the GIA Report Click here: 15319663

0.25

To review the GIA Report Click here: 2185373308

0.25

To review the GIA Report Click here: 5181379638

0.25

To review the GIA Report Click here 1182373544

Total Average Score: N/A of 12

Lot # 1674

11.35 carat Fancy Intense Yellow, Cushion cut, VVS2. High catalog estimation: $26,979 pc

Result: Didn’t reach the minimum

This fancy intense yellow old mine cushion has all the typical characteristics an antique diamond will have; ‘Uneven color distribution’, ‘Fair symmetry’ and a very distinct facet alignment which are considered inferior when seen in modern diamonds. In this case these features will not necessarily create a discount on  the price because buyers who look to own these periodic diamonds, look at these features as a testimony of authenticity. Having said that, it looks as if the stone went through a minor polishing process in recent years to reinforce the inner-grade, but still kept its “Old Look”. Our grading system doesn’t really correspond to older diamonds and as such it will be partial. 

Total Visual Score: –  out of –

To review the GIA Report Click here: 2191412572

General

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