A device for producing a reproducible identification pattern of a polished gemstone includes light directing means for directing a focused beam of light onto a gemstone orientated in a particular known manner to produce an output of the internal refraction and reflection characteristics of the gemstone including reflected light beams having particular locations, sizes and intensities. The device also includes automated means for changing a position of the gemstone relative to the focused beam of light; and also a means for recording the output in a manner to record the relative size and location of the reflected light beams.