Diamonds: The Four Cs - Cut

The Cut of the diamond is the most important and perhaps the most misunderstood and controversial of the 4Cs. Diamond dealers refer to cut as the "make" or "model", and it is the only feature of a diamond that can be controlled by man.

Precision cutting is required to maximize the true brilliance of a diamond. When we talk about cut, we are referring to much more than just the shape of a diamond. We are talking about the exact angles, proportions, symmetry, and polish that affect the way a diamond reflects light. Precision is of the essence. For maximum brilliance to occur, there should be absolute symmetry in the placing of the facets and the highest quality of polishing. When the proportions are ideal the brilliance, scintillation and dispersion of light is maximized.

A skilled diamond cutter realizes the rough diamond's potential. He cuts and facets the crystal to reflect the maximum amount of light inside the stone and back through the top of the diamond. His objective is to produce a perfectly symmetrical stone whose right and left sides are mirror images of each other.

Diamonds cut for weight and not sparkle	Diamonds with well-cut proportions

At the same time, he has to find the optimal balance between yielding the most diamond weight and creating the best proportioned cut. One reason why higher grades of cut are so much more costly is because more diamond was sacrificed to create them. That's also why a well proportioned one-carat diamond may be worth twice as much as a poorly proportioned larger diamond that lacks fire and brilliance.

The way a stone is cut can affect its appearance in other ways. If the diamond has a deep cut, it actually looks smaller than another diamond of the same weight that is cut well. Likewise, a diamond that has a spread cut (cut shallow) will appear larger than another diamond of the same weight that is cut well. A diamond that is cut either too deep or too spread is typically undesirable.