Introduction

Don’t confuse diamond "cut" with "shape." Shape refers to the general outward appearance of the diamond, (such as round, emerald, or pear). When a diamond jeweler (or a diamond certificate) says "cut," that's a reference to the diamond's reflective qualities, not the shape.

The cut of a diamond determines its brilliance. Most gemologists consider diamond cut the most important of the four Cs, so it is important to understand how this quality affects the properties and values of a diamond. A good cut gives a diamond its brilliance, which is that brightness that seems to come from the very heart of a diamond. The angles and finish of any diamond are what determine its ability to handle light, which leads to brilliance.

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. When a diamond cut is shallow light is lost out of the bottom causing the diamond to lose brilliance, and when the cut is deep the light escapes out the sides causing the diamond to appear dark and dull.

Most gemologists agree that the best cut diamonds are those that follow a set of formulae calculated to maximize brilliance. These formulae can be seen in a diamond's proportions, most importantly how the depth compares to the diameter, and how the diameter of the table compares to the diameter of the diamond.

However, the variance in the proportions between an Ideal Cut and a Poor Cut can be difficult to discern by the casual observer.

Because cut is so important, several grading methods have been developed to help consumers determine the cut of a particular diamond. In general, these grades are:

Cut Grades

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.

• Super Ideal Cut
• Ideal Cut
• Very Good Cut
• Good Cut
• Fair Cut
• Poor Cut

Super Ideal Cut

These diamonds are cut to more exacting standards than the finest graded cuts currently available. These diamonds also have an Ideal polish and Ideal symmetry. Super Ideal cut diamonds have the finest cut grade in existence, and as a result its fire and brilliance are unmatched. Diamonds with a Super Ideal cut grade are even more rare and costly than diamonds with an Ideal cut grade.

Ideal Cut

These diamonds are cut to extremely exacting proportions of depth, diameter, and angles that allows for maximum brilliance (white light returning to the eye), dispersion (the play of colors you see in a diamond’s reflections), and scintillation (sparkling flashes that are seen when the stone, light source, or viewer moves). Diamonds with an Ideal cut grade are more rare and costly than a diamond with a Very Good or Good cut grade.

Very Good Cut

These diamonds are cut to exacting proportions that reflect almost as much light entering it as an Ideal cut. Diamonds with a Very Good cut grade represent a brilliant diamond at a lower price than a diamond with an Ideal cut grade. This cut represents the best balance between quality and cost.

Good Cut

These diamonds might be slightly deeper or shallower, or have a slightly larger or smaller table facet compared to a diamond with an Ideal cut, probably resulting from the cutter striking a balance of cut and carat weight retention. Diamonds with a Good cut grade reflect the most light entering them and represent an excellent value.

Fair Cut

These diamonds have been cut to yield more carat weight from the rough diamond. A fair cut diamond reflects light well and represents a much lower price than a diamond with a good cut grade. This cut is the best option for those who want the biggest size for the price.

Poor Cut

At Diamond Manufacturers we do not carry poor cut diamonds due to their lack of brilliance.

What Cut Grade is best to buy?

The answer looks simple, Super Ideal Cut is the perfect diamond with Ideal cut, polish and symmetry, and therefore the best to buy. The average person can’t tell the difference between Super Ideal and Ideal cut diamonds, however everyone can tell the huge difference in price.

For those who have a flexible budget: Ideal

For those people who have a limited budget: Very Good

For those who prefer size over quality: Good or Fair