5mm Australian Opal Bezel Set Stud Earrings, Natural Opal 5mm Stud Earring. These earrings are 925 sterling silver, available in Platinum Plating (silver), Rose Gold, or Gold Plating. These earrings includes a gift box and a certificate of authenticity with purchase. This item is made to order, please allow up to 10-15 days for processing and delivery of this item.