Diamond Education

Cut

Cut is a diamond's most important characteristic. It has the greatest overall influence on a diamond's beauty. It determines what we generally think of as sparkle. It is recommendedthat one should select the highest cut grade within your budget. A polished diamond's beauty lies in its complex relationship with light:
  • how light strikes the surface
  • how much enters the diamond
  • how light returns to the eye
  • in what form light returns to the eye


The result of the complex relationship with light is a magnificent display of three attributes.

Brightness is the combination of all white light reflecting from the surface and interior of a diamond.

Fire describes the "flares" or color emitted from a diamond. Its the prismatic effect.

Scintillation describes the flashes of light you see, when the diamond, the light  source or when the observer moves.

As shown in the images below, when a diamond is well-cut, light enters through the table and travels to the pavilion where it reflects from one side to the other before reflecting back out of the diamond through the table and to the observer's eye. This light is the brilliance we mentioned, and it's this flashing, fiery effect that makes diamonds so mesmerizing.

 

In a poorly cut diamond, the light that enters through the table reaches the facets and then 'leaks' out from the sides or bottom of the diamond rather than reflecting back to the eye. Less light reflected back to the eye means less brilliance.

Which Grade of Cut Should I Buy?

Selecting the grade of cut is really a matter of preference. To make the best selection, you need to understand the various grades. Please note that the descriptions below are general guidelines.

Ideal Cut

This cut is intended to maximize brilliance, and the typically smaller table sizes of these diamonds have the added benefit of creating a great deal of dispersion or 'fire' as well. Ideal quality diamonds are truly for the person who enjoys knowing that he has one of the finest things that money can buy. This category applies only to round diamonds.

Excellent

In the case of round diamonds, many Excellent Cut diamonds have cuts that are the equal of any Ideal Cut diamond, though they often can be purchased at slightly lower prices than AGS Ideal Cuts. They are intended to provide maximum brilliance and fire. Like the Ideal Cut, these are also for the person who enjoys knowing that he has one of the finest things that money can buy.
 

Very Good

These diamonds reflect most of the light that enters them, creating a good deal of brilliance. With these diamonds, the cutters have chosen to stray slightly from the preferred diamond proportions in order to create a larger diamond. The result is that these diamonds fall slightly outside of some customers' preferences in terms of, for example, table size or girdle width, though, in many cases many of the parameters of diamonds in this range will overlap with certain parameters of diamonds in the Ideal or Premium ranges. Generally, the price of these diamonds in slightly below that of Premium cuts.


Good

Diamonds that reflect much of the light that enters them. Their proportions fall outside of the preferred range because the cutter has chosen to create the largest possible diamond from the original rough crystal, rather than cutting extra weight off to create a smaller Premium quality diamond. Diamonds in this range offer an excellent cost-savings to customers who want to stay in a budget without sacrificing quality or beauty.

Fair & Poor

A diamond graded as fair or poor reflects only a small proportion of the light that enters it. Typically these diamonds have been cut to maximize the carat weight over most other considerations.