“Massive” 41.82 Ct. Blue Diamond Found in South Africa

By Rob Bates | January 15, 2026

Petra Diamonds has uncovered a 41.82 ct. blue diamond at the famed Cullinan mine in South Africa, and experts say it’s poised to become one of the most important blue gems ever found.

A Petra statement said the type IIb diamond is of “seemingly exceptional quality in terms of both its color and clarity.”

The company added that it was “in the process of analyzing the stone and ascertaining the preferred method of sale.”

On Only Natural Diamonds, jewelry and watch editor Grant Mobley called the find “massive” and “almost unbelievable,” and said it “could rewrite the record books.”

“Blue diamonds already occupy the rarest tier of natural gemstones,” wrote Mobley. “A blue diamond of this size, recovered from one of the world’s most storied mines, immediately invites comparison to some of the most valuable diamonds ever sold.”

The Cullinan has already produced several famous blues, including the 12.03 ct. Blue Moon of Josephine, which garnered a then-record $48.5 million at auction in 2015, and the 15.1 ct. De Beers Blue, which topped that by fetching $57.5 million in 2022.

Petra purchased the Cullinan mine from De Beers in 2007.

(Photo courtesy of Petra Diamonds)