Forty years ago, while paging through a book sent as an unexpected gift from a friend, Roger Welsch came across a curious reference to stones that were round, "like the sun and moon." According to Tatonka-ohitka, Brave Buffalo (Sioux), these stones were sacred. "I make my request of the stones and they are my intercessors," Brave Buffalo explained. Moments later, another friend appeared at Welsch's door bearing yet another unusual gift: a perfectly...