Cut is the most important attribute in the evaluation of a diamond, as it can affect up to 40% of its value. A layperson can detect, quite easily, when a diamond is not that shiny or brilliant, compared to a diamond that exudes fire and prismatic colors.
A well-cut diamond is polished precisely to the proportions that yield the most light return which is what makes a diamond sparkles. Light enters a diamond through its table (top) and reflects off the cone-shaped pavilion until it comes back through the top, giving the stone that spectral sparkle. If a diamond isn't cut well, the light never comes back up; it leaks out the bottom or sides of the stone and it has little sparkle or life. That's why when grading a diamond its "cut" speaks directly to the skill of the diamond cutter.
Three components comprise "cut." They are: proportions, symmetry, and polish. When evaluating a diamond's cut, experts will ask: Do the cuts on the diamond meet the angle guidelines for maximum dispersion of light? Is the stone symmetrical? Are the stone's surfaces smooth? Are sanding marks visible? All three of these elements greatly affect the quality of the cut and the diamond's value, brilliance, and beauty. All three are taken into account when a grade is assigned to a diamond's "cut". Milanj DIamonds specializes only the top two levels of cut, polish and symmetry.