Cut
The best sapphire cuts offer a depth/width ratio higher than comparable diamond cuts. Expect a depth
percentage of 65% to 80% for good quality sapphires (the depth percentage is depth/width). Stones that
are too deep will look smaller than expected but they will show off more color than they would if
they were cut to normal proportions. Deep-cut stones also preserve weight, increasing the cost of
the stone without the expected increase in the size of the crown (top portion of the gem). Stones
that are too shallow will look big for their weight and appear lighter in color than deeper-cut stones.
Good quality sapphires also have good symmetry when viewed in profile - reflecting the light evenly.
Overall Grade
The overall grade is determined by looking at Hue, Tone, Color-Purity, Clarity, Transparency and Cut.
Overall grade scores: Poor, Fair, Good, Very Good, Exceptional (Best)