5x7mm Australian Opal Stud Earrings, Natural Opal Stud Earrings Platinum Plated. The main gemstones on these earrings are 5x7mm. These earrings are solid 925 sterling silver, available in platinum plating (silver), or rose gold color. Upon purchasing, please include within your order notes or send a message with your metal color choice (silver or rose gold). This item includes a gift box and a certificate of authenticity with purchase. Please allow up to 15-20 days for processing and delivery of this item.