Dive into the fiery depths of man-made opal--a kaleidoscope of opalescent color that dances in the light. All the splendor of natural opal, manufactured into a harder composite (4-5 Moh's scale) that withstands heat and cold. Beautifully resembling natural opals, man-made opals are comprised of approximately 80% silica with 20% added epoxy for hardness and consistency. Colors of the opals are black and yellow with flashes of orange, green and blue. Well calibrated to fit standard cabochon settings.