The brilliance of a diamond is dependent mostly on the cut of the diamond. A well cut diamond has light that bounces and reflects from facet to facet, which causes a diamond to sparkle. If a diamond is cut too shallow or too deep, the light will not reflect as efficiently as it could and the stone will be less brilliant. The quality of the diamonds cut is graded from low to high as follows: poor, fair, good, very good and excellent.
In addition to the quality of the cut, you should also consider the shape of the cut. The shape of the diamond is largely a personal preference. You should consider the wearer’s style and preference before purchasing a diamond. The most popular cuts are round, oval, emerald, cushion, brilliant and princess.