Upper and lower girdle facets add much additional internal reflection (brilliance) to a diamond.

Upper and lower girdle facets include the 32 facets,16 on top, 16 on bottom, that add additional brilliance to a diamond. Many cutters and dealers refer to them as upper and lower halves. Other terms not used as often include: upper and lower break facets; skew facets; skill facets; and cross facets.