Gravitating toward planetary inspiration, these solid gold stud earrings feature boulder opal centers surrounded with a lunar-like array of brilliant-cut diamonds. From Syna's Cosmic Collection. Post-back closure 18k gold, boulder opal and champagne diamond Carat: 0.9 ctw diamond, 2.5 ctw opal Diamond color: I Diamond clarity: SI2 Polish with soft cloth Stones sourced from Australia Imported Measurements Diameter: 0.6in Syna Jewels Women's Cosmic Boulder Opal Diamond Studs in Gold