A black opal, resembling a ball of yarn, has been set near the cat's paw. The black opal exhibits a flash type of color, similar to a cat's eye. It flashes with fluorescent green and blue. It has been set at the angle where these colors appear most prominently. Made with silver925. With continued use, the silver will develop a unique patina, resembling the cat's fur. Materials: silver925, black opal Size: Approximately 1.6cm (height) x 2.2cm (width) Almost just the cost of the loose gemstone! ^^;