The Incomparable is a 407.48-carat faceted, fancy brownish-yellow diamond. It is the world’s third-largest faceted diamond, after the Golden Jubilee and the Cullinan I. It measures 53.90 x 35.19 x 28.18 millimeters in size and is cut into a unique triangular shape named a “triolet.”

The diamond ended up in the hands of De Beers and was sold to Donald Zale, chairman of Zale Corporation; Marvin Samuels of Premier Gems; and Louis Glick, a New York diamantaire. Mr. Samuels designed the cut and accepted the job of cutting the stone.

After cutting, the diamond was displayed at an event celebrating Zale Corporation’s 75th anniversary. Four pieces of information make this diamond especially “incomparable” to any other.

First, The Incomparable is the world’s largest internally flawless diamond. Second, the 890-carat rough from which it was cut was found by a child playing near a pile of rejected ore that her uncle had brought home from a mine dump. This occurred in the 1980s in the Democratic Republic of the Congo.

Third, when Christie’s in London offered The Incomparable in a public auction in 1988, it became the largest diamond ever offered at public sale. Unfortunately, the diamond didn’t reach the expected price of $20 million and it was withdrawn. Fourth, in 2002 The Incomparable was offered for sale on ebay and went unsold – but became the largest diamond ever offered for sale in an online auction.

The Incomparable is a 407.48-carat brownish yellow diamond and the world’s third-largest faceted diamond. It is also the world’s largest internally flawless diamond. It measures 53.90 x 35.19 x 28.18 millimeters. The specimen in the photo is a replica of the famous gem. A one-carat diamond is shown as a size comparison.