Diamond and black opal ring. Size: 15.5 Opal size: Approximately 8.9mm x 6.3mm Ring width: Approximately 3.0mm - 5.0mm Markings: K18 Weight: Approximately 4.2g Accessories: None The black opal features a beautiful play-of-color effect. This is a high-quality black opal with play-of-color visible even from the back of the stone. No cracks or scratches are visible. The images were taken under LED lighting. The diamonds are near colorless and have excellent brilliance. The carat weight is unknown as there are no stone markings. The ring has been polished for the listing and is in excellent condition with no particular issues. The case in the image is for another ring and is not included. Material... Gold