PRODUCT DETAIL METAL 18K Gold Filled SIZE 15" + 3" extender Minimal, chic, and dainty. The sun opal necklace is the perfect way to add some polish to work or play. Fire opal stones encrusted with cubic zirconia crystals with a beautiful, feather-weight chain. 18K gold filled over brass base. STYLE TIP Nothing better than to layer with your other opal pieces from our collection like the dainty I Love Choker. Handmade in the US.