Diamond Cut Grading
Cut is the grading that refers to how well the diamond is cut into its shape: The evenness and proper alignment, angle and size of facets, the absence or presence of extra facets, and the percentage each section of the diamond makes up of the whole. Some gemmology laboratories grade "Ideal" as the best, many only use "Excellent". Most laboratories only grade Round Brilliant Cut Diamonds on their cut, as fancy shapes have many variations and modifications. The best cut diamonds have the most light return - simply put, more sparkle, shine and scintillation.