Sterling Silver 925 - Round Opal Solitaire Stud Earrings White 3mm Description These Sterling Silver stud earrings feature a beautiful round natural Opal gemstone and a push style butterfly post. Metal Material: Sterling Silver; Stone: Opal; Earring Size: 3mm; Backing Style: Push; Shipping: Item will be shipped within 1 business day after payment clears. Shipping Options: Free US Standard Shipping without The Tracking Number.