9ct Gold Opal Earrings with Diamond SurroundOpal and Diamond Earrings These 9ct yellow gold earrings are designed with a central round opal in each stud. Each opal is completely encircled by a halo of individual diamonds, forming a classic cluster effect. The gemstones are set within the yellow gold, which provides a warm toned backdrop. Measuring 5. 7 x 5. 7 mm across the front with a depth of 3. 5 mm, the earrings have a compact and well proportioned profile.