A type of glass that will reflect and transmit different wavelengths of light, thus visually appearing as different colors in reflected and transmitted light; that is, the color differs when the light is reflected off the object and shining through the object. Since glass is not crystalline, the dichroic effect is achieved by coating thin layers of various chemicals on the surface of clear glass. Examples of the chemicals are: zinc sulfate, magnesium fluoride, gold, copper, nickel, cobalt oxide, iron oxide, chromic oxide, or titanium dioxide. Examples of dichroic glass objects are those developed by Roman glassmakers, where dichroic glass was prized for its resemblance to natural stones, both in its color and luminescence.