The Freedom Diamond is the largest cut diamond found in United States and was discovered in the Kelsey Lake Diamond Mine in Colorado in 1997. It is a 16.86 carat cushion cut diamond now set in a beautiful three-stone ring. The stone was cut from a rough diamond crystal weighing 28.20 carats. The Kelsey Lake Mine, where it was discovered, was opened in 1996 but was never commercially successful, meaning not enough diamonds were found to keep it operational. Even though it closed five years later, the fascinating mine left us with a few incredible American diamonds. The mine also remains the only modern diamond mine in American history.