Have you ever seen a diamond that really sparkles, shines and seems almost like it's glittering? That is a well-cut diamond.
A well-cut diamond has been cut from rough so that each of it's proportions are such that light is bounced from angle to angle and reflected within the stone and back to your eye. The cut of a diamond includes the symmetry of the stone, how the angles and facets are proportioned to one another, and how well the diamond's surface has been polished so that it reflects the maximum amount of light. These features all combine to give a cut a grade between poor and excellent.
How well a diamond is cut should be a priority when finding a stone that's right for you. If a diamond has high clarity and color, but is poorly cut, it can look dull and lifeless.
There are three main cutting styles...
1. Brilliant cut: a combination of kite and triangular facets. This cutting style can be seen in round, radiant, cushion, princess, pear, oval, marquise and heart shapes.
2. Step cut: a combination of rectangular and square facets. This cutting style includes asscher, emerald and baguette shapes.
3. Mixed cut: a combination of step and brilliant cut stones. This includes the princess cut and the cushion cut.
The diamond shape only refers to the outline of the stone -- and diamonds come in many different shapes.