The cut refers to the make of the diamond. There are many different cuts to choose from, some of the most popular include Round Brilliant, Princess Cut, Radiant Cut, and Emerald Cut.
The cut is the lesser known of the four C's but of considerable importance as the cut determines the overall appearance and quality of a diamond, and is paramount when producing a diamonds maximum fire and brilliance. Fire and brilliance is what is commonly known as diamonds 'sparkle'. To achieve optimum 'sparkle' a diamond needs to have the correct proportions.
If a diamond is either too deep or shallow, when the beams of light split into their spectral colours and refract through the facets they then leak out of the stone. When a stone is "perfectly" cut all of the light is passed through the table and it refracts throughout the stone and reflects out from its derivation.
