Found in Australia and considered to be the most valuable and rarest opal of all, black opal appears dark from afar, but as you draw closer its ethereal fire can be seen. Our London jeweler pairs rare black opal with gold-plated British sterling silver to handcraft these stunning teardrop earrings. Handcrafted for Uno Alla Volta, from the heart and hands of the artisan. Dimensions - Approx. 1.25'' long, posts.