History
The tradition of wearing an engagement ring dates back to 1477 when Mary of Burgundy, the first known recipient of a diamond engagement ring, received it as a symbol and promise of marriage.
More than 100 years ago, a Russian Mathematician named Marcel Tolkowsky, who was a member of a large powerful diamond family, calculated the number of cuts necessary to create the "ideal" diamond shape, known today as the brilliant cut. Since that time, cutters have been using advanced techniques and mathematical calculations to intensify brilliance and fire.
The Round Brilliant (aka brilliant cut) shape diamond is the most popular of diamonds shapes. It consists of 58 facets and displays the most brilliance, fire, and scintillation of all diamond cuts on the market today.
Round Brilliant Diamond Cut
The cut of a diamond determines its brilliance. A poorly cut diamond will have a dull appearance even if it has perfect color and clarity. The cut is considered one of the most important diamond characteristics by gemologists. It is based on factors that determine the light performance, dimensions, and finish of a stone.
The cut should reflect the maximum amount of light to the viewer's eye. For example, if a diamond is cut too shallow light will be lost out of the pavilion (bottom) and the diamond will lose brilliance. If the diamond is cut too deep, the light will escape through the sides and the diamond will appear dark.
Since Round Brilliant cut diamonds are designed to maximize brilliance, you need to be sure that you are familiar with the qualities of a good cut. A Round Brilliant diamond makes a beautiful engagement ring as a solitaire, an amazing 3 stone ring, or set with other stones.
Round diamonds are classified as excellent, ideal, very good, fair, and poor.
An excellent cut is the highest grade a diamond can receive from the Gemology Institute of American or GIA. Excellent Cut Diamonds have optimal proportions and give the most brilliance and light return.
A very good cut diamond has depth and table percentages that fall just outside the "excellent" requirements set by the GIA. This diamond returns almost all the light and is similar to an ideal cut diamond. A very good cut diamond will sell for less than an ideal cut diamond yet possess very similar characteristics
A good cut diamond reflects most of the light that enters it. A good cut diamond gives you good brilliance and will sell at a much lower price than an ideal or very good cut diamond. "Good" cuts are popular choices for engagement rings.
A fair cut diamond reflects a decent amount of light and will sell for much less than an ideal or very good cut diamond. A fair cut is a popular choice for people who want a decent cost savings to purchase a larger stone.
Recommendations
When buying Round Brilliant cut diamonds, there are a few recommendations for getting the best diamond. We recommend a cut rating of Excellent or Very good.
For budget minded purchasers of Round Brilliant cut diamonds, you should follow the minimum Cut rating of Good.
Color and clarity are something to consider carefully when choosing this cut. The Round Brilliant will give you more flexibility with balancing color, cut, and clarity while still providing brilliance and fire.
Suggested Guidelines for Round Brilliant Diamonds
| Cut |
Excellent |
Very Good |
Good |
| Color |
D, E, F |
G, H |
I, J |
| Clarity |
IF, F, VVS1, VVS2 |
VS1, VS2 |
SI1, SI2 |
| Depth % |
59.0% - 61.0% |
58.5% - 58.9% or 61.1% - 62.5% |
58.0% - 58.4% or 62.6% - 63.0% |
| Table % |
52.4% - 57.5% |
57.6% - 59.5% |
59.6% - 62.5% |
| Girdle |
Medium |
Thin to Thick |
Very Thin to Very Thick |
| Ratio |
1.00 - 1.00 |
1.001 - 1.005:1.00 |
1.006 - 1.01:1.00 |
Quick Glossary
Cut – the proportions and finish of a polished diamond. Many Gemologists believe cut is the most important of the 4 Cs.
Color grading – a system of grading diamonds based on either being colorless for white diamonds or hue, depth of color, and saturation of color for fancy color diamonds. For white diamonds, GIA uses a scale of D-Z in which D is colorless and Z is light yellow. Z should not be confused with yellow fancy color diamonds.
Clarity characteristics – internal or external feature of a diamond that helps determine the quality and establish its identity.
Depth % – a ratio of the total depth of a diamond from table to culet compared to the total diameter.
Table % – the diamond’s table size expressed as a percentage of its average girdle diameter.
Girdle – the outer edge or outline of the diamond’s shape.
Girdle thickness % – girdle thickness expressed as a percentage of the average girdle diameter.