Wonder Stone or Wonder Rock is a common name for a tight graned type of Rhyolite, that is suitable for gemstone use. This rhyolite is banded and has very pleasing colors of plumb, yellow and tans.Wonder Stone is found in many locations thorough the west. (for example, Yellowstone in Wyoming, Long Valley in California, Alder, Montana and Valles in New Mexico) This pendant is 37x15mm (1.46" x .62")Chain not included.