a translucent lens forms an outer envelope portion of the fixture the grating being mounted between the light source and the lens a reflector mounted opposite the light source from the grating enhances light transmission through the grating a semi reflective shell member in front of the light source used alone or in combination with a geodesicly segmented reflector opposite the light source greatly enhances the visual effects of the fixture by projecting multiple images of the light source through the grating a mold for molding the grating includes a large plurality of metallic grating lines corresponding to a diffraction pattern for defining the grating surface a metallic substrate rigidly connecting the grating lines a cavity member for defining portions of a mold cavity the substrate being connected to the cavity member with the grating lines facing the cavity and defining at least a portion of the cavity whereby the grating surface forms a multiplicity of surface discontinuities on a molded article application_number US 38512295 A description the present invention is directed to a decorative lighting fixture for producing colorful visual effects similar to effects that are normally produced by prismatic crystal fixtures with reference to fig1 of the drawings a fixture 10 has a conventional incandescent lamp 12 a centrally located light transmissive.