Huge gem diamond found at Kelsey

The largest diamond ever recovered in Colorado was recently pulled from the Kelsey Lake mine of Redaurum (RRK-T).

The 28.3-carat stone is the fifth-largest diamond ever found in North America (the largest being the Uncle Sam diamond, which weighed 40.23 carats).

The largest stone previously recovered at Kelsey Lake weighed 14.2 carats.

Redaurum is holding its first commercial sale of Kelsey Lake diamonds in Denver, Colo., on Sept. 24. More than 2,500 carats will be sold through a closed-bid tender system.

Kelsey Lake is producing 190 tonnes per hour, with more than 25% of all diamonds recovered weighing more than 1 carat. To date, only the KL-2 pipe has been used to feed the plant, though production from the KL-1 pipe is set to begin in November.