A diamond’s proportions are the most important factor for determining how well a diamond will sparkle. Diamond Proportions refer to the crown angle, pavilion angle, and the relative measurements of its facets. The proportions are the reason for a diamond’s overall appearance. The facets act as tiny mirrors, and their size and placement affect how light passes through the diamond.
A diamond that has proper proportions will reflect all the light back to your eyes, delivering brightness, fire and scintillation. Poor proportions by contrast, shallow and deep cut diamonds, will lose most of the light through the bottom of the diamond. The brilliance is dulled, and the diamond becomes less radiant.
The Gemological Institute of America (GIA) has found that there is no exact proportions that define a properly-cut round brilliant diamond. Different sets of proportions can receive the same cut grade in their grading reports. The proportions have a direct impact on the brilliance of the diamond, but the visual appearance is the most important factor. Don’t focus too much on the exact proportions so long as the diamond is cut in a way that allows light to pass through it effectively. Diamond experts can help determine this, but it will often be apparent simply by looking at the stone.
When shopping for round cut diamonds, I highly recommend “excellent” cut diamonds (if grading is done by the GIA), or “ideal” cut diamonds (if graded by the AGS). This will allow for the most light to pass through the diamond delivering that ultimate beauty.
A diamond’s proportions are incredibly important, but don’t let it be the only factor when selecting a diamond. RH Bockstruck can help lead you to the perfect stone that will last a lifetime.