World's largest square emerald cut diamond, a 302.37-carat gem, now on sale

By Polly Mosendz

In the market for a piece of statement jewelry? Would 302.37 carats of diamond be enough of a statement for you? Graff Diamonds announced Wednesday that the largest square emerald cut diamond in the world is available for sale. The price was not disclosed.

The finished stone, named Graff Lesedi La Rona, is the principal diamond from the 1,109 carat Lesedi La Rona rough diamond found in 2015 in Botswana. Lucara Diamond Corp. sold the Lesedi La Rona to Graff Diamonds for $53 million—a cool $47,777 per carat—in 2017.


The sheer size of the diamond posed a challenge for the Graff gemologists tasked with analyzing, cutting, and finishing the stone: It was too big for their equipment. A new scanner had to be built specifically for this rough diamond; it is equipped with specialized imaging software to map the stone and determine what kind of cut would lead to the largest, most brilliant diamond. The entire process took more than 18 months, according to the company.

“Cutting a diamond of this size is an art form, the ultimate art of sculpture,” Laurence Graff, founder of Graff Diamonds, said in a statement. “It is the riskiest form of art, because you can never add and you can never cover up a mistake; you can only take away. You have to be careful and you have to be perfect.”

In addition to the Graff Lesedi La Rona, 66 “satellite” diamonds resulted from the rough stone. The siblings range from less than a carat to more than 26 carats.