Christie’s to auction largest fancy blue diamond ever offered, estimated at $8.5 million

The Azure Blue is the kind of stone that changes the terms of the conversation. Christie’s will place the 31.62-carat pear-shaped fancy blue diamond at its Magnificent Jewels sale on June 9 at Rockefeller Center in New York, with an estimate of $6.5 million to $8.5 million and the claim that it is the largest fancy blue diamond ever offered for sale at auction.

That scale matters, but so does the paperwork behind it. Christie’s says the Gemological Institute of America graded the diamond natural color, fancy blue, potentially Internally Flawless, and described its color as having exceptional uniformity. In a market crowded with blue-tinged claims, those words separate a true rarity from a stone that merely photographs well. The pear shape also helps the color read across the face of the diamond, giving the blue more uninterrupted surface to hold the eye.

Christie’s is presenting The Azure Blue in collaboration with The Fine Art Group, and the framing is deliberate. This is not simply a big stone with a dramatic estimate; it is a benchmark lot meant to stand beside the most consequential colored diamonds of the last decade. Blue diamonds sit near the top of the rarity ladder, and auction history explains why. The 12.03-carat Blue Moon of Josephine sold at Sotheby’s Geneva in November 2015 for $48.4 million, while the 14.62-carat Oppenheimer Blue brought $57.5 million at Christie’s Geneva in 2016. Those results turned exceptional blue diamonds into auction events that collectors still measure against.

The Blue Moon of Josephine set a record as the most expensive jewel ever sold at auction, a reminder that size alone never tells the whole story. With The Azure Blue, Christie’s is offering a different kind of benchmark: the largest blue diamond ever to come to auction, backed by a GIA report that places its color and clarity in the highest conversational tier. The house is also bringing a second blue diamond to the same sale, a 5.04-carat fancy vivid blue marquise-cut stone with the same $6.5 million to $8.5 million estimate, a striking sign that the market for top blue stones extends well beyond headline carat weight.

In vintage jewelry, the best stones read like archives. The Azure Blue reads as a rare page in the history of natural color, one that collectors will measure not just by carats, but by how few diamonds in the world can honestly stand beside it.