An apparatus and associated method for the direct and objective grading of the cut and symmetry of gemstones is provided. The apparatus comprises a laser, an integration sphere, and a gemstone holder, which together measure certain optical characteristics of the gemstone. Optionally, the gemstone holder mechanically rotates and the integration sphere connects to a data recorder such that a plurality of measurements may be recorded and analyzed. The associated method provides a method for interpretation of the data generated by the apparatus as the data relates to the cut quality and symmetry of the gemstone.