Diamond Cut Stones:
The cut of a diamond as a value factor refers to its proportions , symmetry and finish. It is not to be confused with its shape. Proportion refers to the angles and relative measurements of a polished diamond. More than any other feature, proportions determine a diamond's optical properties. Studies have shown that table size, crown angle, and pavilion depth have a dramatic effect on a diamond's appearance.
Symmetry is a grading term for the exactness of shape and placement of facets. Variations in symmetry include off-center culets and tables, poor facet alignment, misshapen facets, out-of-round girdles, and wavy girdles.
Shapes other than the standard round brilliant shown above are called fancy shapes or fancy cuts. Their names are based on their shapes. The best known are the heart, marquise , pear shaped cut , emerald cut , oval , radiant, and princess.