Synthetic Blue Opal Infinity Pendant Sterling Silver Necklace 18 Inches Share this 18in necklace with someone you love eternally and infinity. This 0.39in, sideways figure 8 pendant is sterling silver with inlay-ed synthetic blue opal and great for that loved one with modern style. Measure: 0.39in With 18.5in Chain, Weight: 5 Grams, Opal: 7mm x 2mm, Material: .925 Sterling Silver, Synthetic Blue Opal