Pre-Auction Impressions: April 20th 2016, Christie’s New York

Our pre-auction analyses focus on visual elements that are not expressed on the GIA report, such as “inner-grade”, “undertone” and “color dispersion”. We use grades 1, 2, 3, 4 and 4+ to evaluate these features. It is often difficult to identify these characteristics when viewing stones in an auction catalogue.

On Tuesday, April 19th, Christie’s will feature a selection of fancy color diamonds.

Lot #244

10.07 carat, Fancy Intense Purple Pink, Cushion, F, VS1. High catalog estimation: $1,191,658 per carat
Price Realized: $878,351 pc (Updated 21/4/16)

This stone exhibits an attractive and sweet undertone and according to the GIA’s color definition, indeed it has a strong presence of purple. The color dispersion is quite good, but the inner-grade (2) is weak. When viewed in person, the stone does not correspond to the image in the catalogue in regard to color intensity or undertone. The stone has a very thick girdle and as a result it does not compare to its weight. Due to visible graining, the crystal is not as clear as one would expect it to be. Although this stone is not perfect, it is important to note that it is still a very rare and commercial gem.

Lot No. 126: A 54.62 carat, cushion-cut, Fancy Vivid Yellow, VVS1 diamond. High catalog estimation: $45,770 per carat
Price Realized: $45,056 pc (Updated 21/4/16)

This Vivid Yellow diamond exhibits a pleasant undertone, even color dispersion and a high inner grade (3). When viewed in person, the stone is relatively close to its image in the catalogue. Manufacturers of large Vivid Yellow diamonds typically pursue the maximum yield and in most cases the stones do not correspond to their high carat weight – but this stone appears larger than expected.

Lot #168

A matching pair of 3.01 carat, round brilliant-cut, Fancy Vivid Yellow, VS1 and VS2 diamonds. High catalog estimation: $107,973 per carat
Price Realized: Didn’t reach the minimum (Updated 21/4/16)

This matching pair of diamonds has the strongest possible inner-grade (4+) that a Vivid Yellow can achieve. The undertone is very good and corresponds to a true primary yellow. These two characteristics together result in a very pleasant and rare combination, especially for stones originating from the Zimmi area in Sierra Leone, which usually embody a brown or green undertone.

When examining both stones face up, it is clear that the bottom pavilion angles are cut differently. Although this visual effect can be spotted by professional diamond manufacturers, the end-consumer will not notice the distinction. Both stones are more impressive when viewed in person than in the catalogue.