The red area on this chart represents the lowest HCA scores. Stones near the center of the red region, those with the lowest scores, are often the least affected by small symmetry variations. A shallower stone, on the lower part of the chart, will look darker when viewed from close up, they are not for everyone. Shallow stones have the advantage of a bigger spread. They are better suited for use as pendants and earring stones where they are not usually viewed from very close proximity (a close observers head obstructs light sources that would otherwise be returned). Deeper proportioned stones, near the upper part of the red area, have more leakage. Leakage means reduced light return. A limited amount of reduced light return can contribute to a diamonds contrast. Diamonds with a large area of partial leakage table, seen as a pale pink area with an Ideal-Scope, are best set in open backed rings so light can get in the bottom or pavilion of the diamond. It is possible for light entering the pavilion to leak back out the top as firey dispersed colored flashes. Deeper diamonds that have perfect or hearts and arrows grade symmetry, with scores around 2, will often perform far better than diamonds of lesser symmetry.