The circular brilliant-cut diamond of 37.08 carats being offered in this sale is a truly exceptional gemstone. It is the largest circular-cut F colour diamond to have appeared at auction and is graded by the Gemological Institute of America as having the rare combination, in such large diamonds, of excellent polish, excellent symmetry and excellent cut (a new grade only warranted for circular-cut diamonds of superior status).
In order to cut a round diamond there will always be a far greater weight loss from the original crystal than there would be with any other shape, like a pear, heart, marquise or rectangle in order to best fit the irregular shape of the fractured crystals that are predominant. Also, when the colour of the diamond crystal is extremely high, as is the case here, there is even less incentive to cut a round stone and lose 50-60 percent of the weight of the original crystal. This is clearly reflected in the table of comparisons below that lists the largest F colour circular-cut diamonds sold at auction