Shape vs Make
Make of a diamond refers to how well a stone is cut and faceted to bring out the full beauty of the rough crystal. Good Proportions, Symmetry, and Polish effect the beauty of a diamond much more than perfect Color or Clarity.
With all the attention given to the Four C’s of diamond evaluation (cut, color, clarity and carat weight), the make is actually the single greatest factor in the beauty. In recent years, GIA and AGS are the major labs that started offering Cut Grades for Round Brilliant Cut diamonds.
Color, shape, clarity and Carat weight determine the rarity and 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 diamond’s unique combination of durability, rarity and potential beauty that makes it so valuable.
Proportion is the single most important factor, because it determines Light Performance 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. However, it is good news that AGS has received a grant to research and publish guidelines for fancy cuts in the next few months.)
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, and for good reasons. Stones with these ideal proportions are noticeably more beautiful to most people. 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. Ideal Cut diamonds include name brands such as Hearts and Arrows, Hearts on Fire, Eight Star, and others.