How cut affects the value of sapphire

How well a sapphire is cut affects its value and beauty.  A well cut sapphire reflects the maximum amount of light and dazzles the viewer with sparkle.  A poorly cut sapphire will have uneven facets and will let light escape rather than reflect.  Note that when it comes to a gemstone's cut, the quality affects the vale not the shape.

Because natural sapphire is such a precious material, and it naturally forms in shallow, short crystals, a cutter will often cut it too shallow rather than cut away valuable material.  This means that most of the sapphires available are cut in such a way that they are too flat.  A sapphire that is cut too flat (called "fish eye") lets light escape though the bottom rather than reflecting it.

Neelam cut
Blue sapphire cut
Buy Ceylon Neelam
Very Poor Cut: We have a slight side view of this sapphire gemstone, allowing us to see how shallow it has been cut.  This gemstone reflects very little light. "fish eye": This cut is better, but still disappointing.  We see sparkle around the edges, but none in the middle. Mediocre cut: There is more sparkle in this saphire but if you look closely, you will see that the facets are uneven. Excellent cut: The cut of this sapphire is perfect.  light is reflected  from each facet inside the stone and the facets are neat and even.