Pre-Auction Analysis: July 22nd 2020, Christie’s Geneva Magnificent Jewels 

The Christie’s Geneva auction is the fourth major auction since the beginning of the Covid-19 lockdown. So far, the overall results reflect a stronger demand to what was expected during this economic crisis, especially in regards to the relatively low quality of the selection presented for sale.     

Our Christie’s Geneva 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 #196

5.34 carat Fancy Vivid Blue, Pear, IF. REZA. High catalog estimation: $2,392,788 per carat

Click here to check the rarity of this stone

Price realized: $1,758,262 pc

A relatively large, Fancy Vivid Blue Pear Shape, with strong saturation and very little gray undertone. Buyers should pay attention to the unusual pointy triangular outline of the stone. In fact, the uncommon gold mounting was probably done in an attempt to give the stone a more traditional shape.       

Total Visual Score: 9 out of 12

To review the GIA Report Click here 

Lot #178

104.04 carat Fancy Intense Yellow, Pear, IF. High catalog estimation: $35,820 per carat

Price realized: $24,976 pc

A very large, Intense yellow diamond with an uncommon shape. Odd shapes in diamonds are usually made out of a weight constraint. The 75% depth and the odd shape indicates that the main motivation during the manufacturing process was to keep the diamond’s weight above the 100ct, rather than complete a classic pear shape shape. 

Total Visual Score: 8 out of 12

To review the GIA Report Click here 

Lot #193

Twelve Fancy Vivid Yellow Marquise and Oval-Shaped diamonds of 5.40 to 2.20 carats, for a total of 41.80 carats, average weight: 3.48ct. Signed Cartier

High catalog estimation: $63,683 per carat

Price realized: $62,130 pc

A very rare ensemble of old mined, Vivid Yellow Marquises, with high saturation and undertone. In this case the whole is larger than the sum of its parts. The fact that so many similar stones in large sizes were grouped together in one piece of jewelry, signed by Cartier, should be taken into account when calculating the price per carat of each separate stone.  

Total Visual Score: 10 out of 12

GIA Reports:

5.40ct, 4.54ct, 4.20ct, 4.16ct, 3.97ct, 3.71ct, 3.45ct, 2.84ct, 2.58ct, 2.45ct, 2.30ct, 2.20ct

Lot #188

2.01 carat Fancy Vivid Pink, Radiant, SI1. High catalog estimation: $794,619 per carat

Click here to check the rarity of this stone

Didn’t reach the minimum

Picture not available

Generally speaking, Vivid Pink Diamonds above one carat are very rare and sought after. In this particular case, the stone’s translucency is quite low due to heavy internal graining. The cavity, etch channel, natural and indented natural are quite prominent in the pavilion.     

Total Visual Score:  8 out of 12

To review the GIA Report Click here

Lot #194

17.81 carat Fancy Vivid Yellow, Pear, IF. Signed Graff. High catalog estimation: $71,743 per carat

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Didn’t reach the minimum

A large, Vivid Yellow Pear shape with very good visual qualities. This stone has both a strong inner-grade and high color dispersion. The hue has no green or brown undertone and exhibits an absolute yellow color.

Total Visual Score: 10 out of 12

To review the GIA Report Click here 

Lot #142

1.01 carat Fancy Deep Blue, old European brilliant cut, SI2. High catalog estimation: $632,548 per carat

Didn’t reach the minimum

Although small in size, this round stone is considered to be a very rare specimen in the landscape of Fancy Color Diamonds. This is mainly because most Fancy Color Diamonds do not come as a round, brilliant cut, moreover in the blue diamond family. The hue in this stone exhibits a solid, ‘‘Ink blue’ color. High saturation and color dispersion are both inherent in most ‘Fancy Deep’ color diamonds. The SI2 clarity is quite hidden when mounted in a ring as it is situated next to the girdle.

Total Visual Score: 12 out of 12

To review the GIA Report Click here

Lot #186

20.31 carat Fancy Intense Yellow, Pear, IF. High catalog estimation: $26,213 per carat

Click here to check the rarity of this stone

Price realized: $21,126 pc

A relatively large Pear Shape, with a warm undertone and a low color dispersion. The inner-grade is below the average “Intense”

Total Visual Score: 6 out of 12

To review the GIA Report Click here

Lot #145

31.07 carat Fancy Yellow, Cushion, IF. High catalog estimation: $15,421 per carat

Click here to check the rarity of this stone

Didn’t reach the minimum

A large fancy yellow cushion cut with low inner-grade and undertone. 

Total Visual Score: 7 out of 12

To review the GIA Report Click here 

Lot #163

2.01 carat Fancy Purple, Radiant, VS2. High catalog estimation: $264,873 per carat

Price realized: $194,026 pc

Single color, Purple Fancy Color Diamonds are more rare than Fancy Red diamonds in equivalent sizes. In most cases, solid purple diamonds don’t leave up to their color expectations and tend to disappoint in their visual appearance. However, in this case, the inner-grade is quite strong and exhibits a desirable lavenderish color. The color dispersion is low and seen only in the table area, leaving a colorless “crown”. 

Total Visual Score:  9 out of 12

To review the GIA Report Click here

Lot #164

1.52 carat Fancy Pink, Pear, IF. High catalog estimation: $77,057 per carat

Click here to check the rarity of this stone

Price realized: $79,617 pc

A Pink Pear shape featuring low visual properties. The pink color is located on the pointy and rounded sides only, leaving the center completely colorless.

Total Visual Score: 6 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.