Boulder Opal Ring (Size 7.5)Look at those streaks of rainbow across the dark brown face of this boulder opal stone. The reflective specks remind us of a starry night sky. We love the way this ring turned out with the hand stamped, split band and this one of a kind stone. . 925 Sterling Silver. Size 7. 5 Handcrafted by Chandra & Andy Derrick in Tucson AZ. Packaged Mindfully with post recycled paper products as well as recyclable packaging.