Ethiopian Opal & Tunduru Colour Change Sapphire & Sterling Silver Ring Size K. This design is part of the Gems Tv Annabella Collection It has a beautiful design to show off the quality of the gorgeous and fantastic gemstones. It comes with its certificate of authenticity. This stunning Ethiopian Opal is really amazing and has a wonderful colour play which is so much more vivid than the photo's. It weighs 2.9 grams. It is an 1.130 carat oval cut Ethiopian opal measuring 9 mm by 7 mm. It is in excellent condition with its certificate of authenticity and luxury ring box.