Pre-Auction Analysis: July 9th, 2020, Christie’s Hong Kong Magnificent Jewels

As most of the industry has been prevented from flying during this special period and inspect the lots physically, we believe this current analysis is even more relevant than ever. 

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.

• I took all images in this article review with an iPhone 11pro, no filters were applied.
• All auction valuations are per carat and in US Dollars.

Lot #1947

12.11 carat Fancy Intense Blue, Marquise, IF. High catalog estimation: $1,017,003 per carat

Price realized: $1,303,971 pc

This stone is a specimen from a period when Fancy Color diamonds were cut exactly like colorless diamonds and a Marquise cut diamond was a very popular shape. Large Fancy Color Marquise shape diamonds are no longer in high demand, however they fall under the category of an “old world-exotic shape”. 

Its facet alignment indicates it was polished in the previous decade and as such exhibits a poor color dispersion, where most of the color is located at the two far opposite points. The blue undertone has no gray in the color mix and exhibits an absolute “Sky” Blue. The inner-grade is above average for an Intense.  

Total Visual Score:  8 out of 12

To review the GIA Report Click here

Lot #1931

4.14 carat Fancy Intense Yellow, Radiant, SI1. GRAFF. 

4.07 carat Fancy Intense Yellow, Radiant, SI2. GRAFF. 

High catalog estimation: $18,948 per carat

Price realized: $18,664 pc

A pair of two Radiant cut diamonds with relatively low clarity for jewelry made by an international luxury brand. Due to the fact they don’t have the same undertone, one can say the stones have low compatibility.

4.14

To review the GIA Report Click here

Market Prevalence for a single stone: A mere 4 to 9 similar diamonds enter the market yearly

4.07

To review the GIA Report Click here

Market Prevalence for a singlr stone:  A mere 1 to 2 similar diamonds enter the market yearly

Total Average Score:  9 out of 12

Lot #1930

2.08 carat Fancy Intense Blue, Marquise, IF. High catalog estimation: $560,947 per carat

Price realized: $714,973 pc

Similar to Lot #1947 this stone was probably manufactured in the previous century and is polished according to ‘old world’ standards. The Inner-Grade is below average, as well as the color dispersion. The color has a noticeable amount of gray. 

Total Visual Score: 6 out of 12

To review the GIA Report Click here 

Lot #1929

7.03 carat Fancy Vivid Yellow, Cushion,VS2. High catalog estimation: $92,205 per carat

Price realized: $70,574 pc

An old mine Cushion with exceptional visual characteristics. The Inner-Grade is very high and exhibits an absolute yellow hue with no green or brown undertone. The depth percentage is high for a cushion (74.8%) which makes the stone look smaller in relation to its weight. However, when it comes to antique diamonds this feature is quite normal and shouldn’t affect the price.

Total Visual Score:  12 out of 12

To review the GIA Report Click here 

Lot #1887

2.01 carat Fancy Pink, Pear, VS1. High catalog estimation: $51,598 per carat

Price realized: ִ$88,272 pc

A Fancy Pink Pear shape with low color dispersion, fair symmetry and a very high depth percentage (74%).  

Market Prevalence: A mere 3 to 7 similar diamonds enter the market yearly

Total Visual Score: 7 out of 12

To review the GIA Report Click here 

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.