Unlike some transparents, the silver irid shows very well on the black background.Cold Characteristics Although termed an opal due to its almost total lack of light transmission, this is (in terms of its composition) actually a transparent glass. Working Notes Low viscosity. Will flow sooner and more than other glasses. In very thin sections the color may vary from reddish/gray to bluish/gray.Photo above is an image of the glass, actual color may differ slightly.
