Sterling silver buckle inlaid with sugilite, coral, lapis, and turquoise with 14k gold accents by Ben Nighthorse Campbell.  Measures 3 1/4" x 2 1/4".  Fits a 1 1/2" belt.  Featured in

North American Indian Jewelry and Adornment : From Prehistory to the Present by Lois Sherr Dubin.