Diamond Cutting

As explained in the last lesson about Shape, the cut of a diamond refers to two different things: the Shape and the Make, or quality of the cutting.

Now it’s time to talk about the Make of a diamond.

Make of a diamond refers to how well a stone is cut and faceted to bring out the full beauty of the rough crystal, whatever shape is chosen. Good proportions, symmetry, and polish effect the beauty of a diamond much more than general color or clarity, because the cut determines the flow of light into and back out of the stone to your eye. Light Performance is king.

Color, shape, clarity and carat weight determine the rarity and thus much of the value of a diamond, but the make determines its beauty. Without any cutting, bruting, faceting or polishing, a rough diamond might very well go unnoticed in a pile of rocks. It is the craft of the cutter that brings all the unique qualities of a diamond and makes it stand out from other crystals and rocks you might found on the ground. That, and the diamond’s unique combination of durability, rarity and potential beauty that makes it so valuable.

The Proportions are the single most important factor, because it determines the flow of light more than other quality factors. Proportions that are too deep or too shallow both allow light to leak out the bottom and lessen the amount of light that strikes your eye.


Diamond proportions have evolved over the last 100 years to increase the brilliance, scintillation and fire to dazzle the eye. Many details must be precisely managed and executed to create a truly beautiful diamond of excellent make.

Proportions determine a diamond’s brilliance (amount of light reflected back to your eye), fire (the flashes of color due to prismatic separation into the colors of the rainbow) and scintillation (sparkling movement of light as you move the diamond).


Below are the approximate proportions to create a round diamond of maximum beauty, achieving an excellent balance between brilliance, fire and scintillation. (NOTE: These proportions only apply to round diamonds. Detailed guidelines have not yet been determined for other shapes, or at least there is not an agreement about an industry standard. Everyone has their own preferences and ways of describing their conclusions. As yet, there is not a universal agreement. However, it is good news that AGS has started giving grades to Princess Cuts, and we hope to see other shapes get a cut grade at some point.)


In addition to the proportions, polish effects the final cut grade too. A well-polished diamond produces sharp sparkle and undistorted brilliance and fire. If the polish is poor, even a well-proportioned, symmetrical diamond can look dull or fuzzy.

Ideal Cut diamonds from many manufacturers have become popular in the past few years. Stones with such precise proportions are noticeably more beautiful to some people, but the difference may not be apparent to everyone.

These are in high demand, however, and usually require more loss of the rough to achieve ideal proportions. These factors combine to cause a slight premium in price.

Super Ideal Cut diamonds are a further development. They include name brands such as Hearts on Fire, Eight Star, and many others. These are sold as super-precise cuts, that produce extremely precise patterns that can be seen under certain magnifying viewers, to show heart patterns from one side, and arrow patterns from the other side.

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Trademarked, branded, patented cuts like these will come with a high premium and may not be worth it if you cannot see enough difference, especially after you wear it for a few days. But to some, the story and the precision is enough to be worth the extra cost. Things like that are totally up to you.

to you.

NEXT :: Diamond Cut Grades

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