July 19, 2003
During a visit to Crater of Diamonds State Park in Arkansas, a friend and I spent an afternoon digging for diamonds in the only diamond mine in America open to the public. The 37-acre field is the eroded surface of an ancient, volcanic pipe. More than 75,000 diamonds have been found at Crater of Diamonds. Any gems you unearth at the park (large or small) you can keep. The largest diamond ever found there was a 40.23-carat beauty called "Uncle Sam." It's the largest diamond ever unearthed in the United States. It takes millions of years for a diamond to form out of pure carbon. The hardest substance known, diamonds form 75 to 120 miles (120-200 kilometers) below the surface of the earth. When temperatures and pressures are exactly right, carbon atoms bond to make "a girl's best friend," the diamond.