When Kevin Kinard was seven years old, his school went on a field trip to Arkansas’ Crater of Diamonds State Park. For the last twenty-six years, he has been going back to the park in search of diamonds. It is not a crazy quest. Since 1906, seventy-five thousand diamonds have been unearthed in the park, but Kevin always came home empty-handed. That is, until September of last year. On Labour Day weekend, Kinard and some friends went back to the park and he picked up anything that looked shiny or interesting. By the end of the day, he had a bag full of rocks...