Fifty years have passed since the recovery of the world's largest octahedral diamond, which to this day remains untouched, unpolished, and unsold.

Dating back to April 17, 1974, the 616-carat Type 1 yellow diamond originates from the Dutoitspan Mine in Kimberley, South Africa. This mine, operational since the 1870s, ceased operations in 2005.

The discoverer of the diamond, De Beers employee Abel Maretela, was generously rewarded with a substantial bonus and a house.

Al Cook, CEO of the De Beers Group, had the privilege of viewing the diamond during a visit to Johannesburg, courtesy of Moses Madondo, CEO of De Beers Group managed operations.

In a LinkedIn post, Cook expressed his fascination with diamond history, stating, "As a geologist, I am deeply intrigued by the origins of diamonds, even predating their discovery."

He explained that the Type 1 classification of the diamond indicates its formation approximately 150 kilometers beneath the Earth's surface, within the mantle, over a billion years ago.

During the Cretaceous period, roughly 100 million years ago, a kimberlite volcano brought this diamond to the Earth's surface. Its striking yellow hue is attributed to nitrogen atoms trapped within the carbon lattice during its formation in the mantle.