If the platform is Macintosh, use the Macintosh style sheet. History has proven that cutting a diamond with 58 facets allows the maximum amount of light to be reflected through it.
Many people confuse the cut with the shape of a diamond.
The shape is largely a matter of personal preference and does not affect the value per se. The Different Facets of a Round Brilliant Cut Diamond. How a Diamond Handles Light. When a diamond is cut to good proportions, light is reflected from one facet to another and then dispersed through the top of the stone. If the cut of the diamond is too deep, light escapes through the opposite side of the pavilion.