The cut of a diamond should not be confused with its shape. Shapes are overall outline which are cut from the original rough diamond, whereas, the cut of a diamond refers to its proportion. The cut of a diamond determines a diamond's brilliance and it is also an objective measure of a diamond’s brilliance and fire.
In an ideal cut diamond, light is reflected from one facet to another and then dispersed through the table of stone. If it is cut too shallow, light leaks out of the bottom; too deep and it escapes out of the side.
Diamond Cut Grades:
The cut grade is calculated by using a optical measuring devise “Sarin machine”, which measures the proportions and angles of diamond cut. The Gemmological Institute of America (GIA) introduced the cut grade on 1st January 2006 for the Round Brilliant diamond. Currently there is no other cut grade for any other shape. The options for the cut grade from GIA are poor, fair, good, very good and excellent.
Similarly, GIA has also introduced grading for Polish and Symmetry. The polish grade refers to how smooth are the diamond facets, whereas the symmetry refers to how well diamond facets are aligned. The grades for polish and symmetry are poor, fair, good, very good and excellent.
Morika Jewellery offers “Good”, “Very Good” and “Excellent” grades of cut, polish and symmetry.