Abstract: Systems and methods for evaluating an optical property of a gemstone operate to trace selected and ordered model light rays through a model of the gemstone. The rays may be selected such that, when ordered into a sequence, the points of contact of successive rays with the gemstone surface generate a pattern defined by a path created by the linking of successive contact points with line segments. Further, the rays may be propagated through the gemstone in a manner that utilizes an ordered set of facet identifiers corresponding to facets impinged upon by a ray previously propagated through the gemstone. Moreover, these strategies can be combined by propagating an ordered sequence of rays corresponding to an ordered set of contact points generating a pattern defined by a path, and using for such propagation an ordered set of facet identifiers corresponding to facets impinged upon by a ray previously propagated through the gemstone.