What do the angles and relative measurements of a polished gem describe?

The angles and relative measurements of a polished gem specifically define its proportions. Proportions are crucial as they affect how light interacts with the diamond, influencing its brilliance and overall appearance. The cut of the gem—referring to the geometry and angles that determine how light enters and exits the stone—plays a vital role in determining its visual appeal.

In terms of diamond grading, proportions are assessed to ensure that the cut maximizes the stone's light return, contributing directly to its sparkle and fire. For instance, the table size, depth, and crown angle are key measurements that when evaluated together provide a comprehensive understanding of how well the diamond has been cut. Proper proportions enhance a diamond's aesthetic qualities, thereby increasing its desirability and value.

While clarity relates to the presence of inclusions and blemishes, symmetry involves the alignment of the facets, and finish determines the surface quality after polishing. Each of these parameters has its own distinct significance in diamond evaluation, but they do not directly encompass the specific angles and measurements that are critical in defining the proportions of a polished gem.