This opal is a shell fossil opal doublet mined in Queensland, Australia. It exhibits gorgeous ocean color of aqua blues and greens. I've framed it with faceted rondelles of swiss blue topaz, tsavorite garnet and tanzanite on 18k gold headpins. The bezel is 22k gold for rich gleam and the argentium* sterling silver base and band have been given a soft satin finish. Measures a US size 6 1/2. Can be sized up to 6 3/4 or 7.