Scintillation Archives - Knox Jewelers

Definition

A Round Brilliant Cut is the modern era’s most popular selection for diamond jewelry. This perfected cut represents six generations of skilled cutters’ efforts to create the maximum light return in a diamond. A Brilliant Cut has a circular outline and a cone-like shape, with faceting patterns that create areas of light and dark contrast. Its triangular and quadrilateral facets are strategically placed to provide exceptional scintillation through the top facet of the gemstone, or its table. The faceting pattern of the modern Round Brilliant was developed in 1919 by Marcel Tolkowsky. Hailing from a family of diamond cutters, Marcel’s cut is based off mathematical calculations that took into account both the maximum brilliance and fire of a diamond. It is referenced to as a ‘Round Brilliant’ to distinguish it from earlier round shaped diamond cuts. The modern round cut consists or either 57 or 58 facets. There are 33 on its crown, or top, and 25 on its pavilion, or bottom. A round brilliant may or may not include a culet, or the bottom-most point facet. Tolkowsky found that if a diamond is cut too shallow or too deep light can escape out of the side or bottom of the gemstone, resulting in the loss of brilliance and fire.

Round Brilliant Facet Diagram

Considering a Round Brilliant Cut

Round Brilliant Cut diamonds are admired for their exceptional fire and modern aesthetic. Nearly 75% of diamonds sold in today’s marketplace are round shaped. The Gemological Institute of America, or GIA, introduced the 4Cs grading system to judge diamonds, with its cut grade exclusively created to evaluate Round Brilliant diamonds. A cut grade will determine how well a gemstone interacts with light. A well-cut diamond will reflect light within itself, from one mirror-like facet to another. If a diamond is dark it means it has been cut too deep or too shallow and light is being lost through the side or bottom. This reduces its brilliance and value, and for this reason we recommend a cut grade of no lower than Excellent or Very Good when shopping for a Round Brilliant diamond.

A Round Brilliant’s faceting pattern will hide a small amounts of body color when face up, but we still recommend choosing a diamond above a I color grade to insure a near colorless stone. When selecting a clarity grade for a Round Brilliant we recommend anything in the VS1 to SI2 range. A stone graded above an SI1 should be eye clean. Clear diamonds can be found in the SI1 and SI2 range, but it is best to evaluate them in person to determine if their characteristics are distracting or unnoticeable.

Knox Jewelers is here to help you create a one-of-a-kind custom engagement ring. If you are considering a Round Brilliant center stone, our design consultants can walk you through all of your options and help you choose your perfect diamond. Contact us today to get started on your custom design.

Have you ever looked at a diamond and wondered why some diamonds are more attractive than others? While some are bright and flash with a rainbow of colors, others look dark and lifeless? These differences are all based on the cut and shape of a diamond. Cut grade fuels a diamond’s overall visual appeal in fire, sparkle and scintillation.

The light behavior within a diamond directly correlates to how well a diamond is cut. GIA recognized this relationship of a diamond’s cut and the quality of fire and the return of white light. Developing a grading system that quantifies specific measurements, angles, and percentages GIA was able to determine parameters that embody the best qualities in the cut of a diamond.

Untitled-1-300x108 Diamonds — GIA's Diamond Cut Grade: Example of a Round Brilliant Excellent Cut and Poor Cut

GIA began their 15 year study on the round brilliant by creating a computer model to examine light behavior within a diamond. Developing proportion-based metrics from this model they were able to predict a diamond’s performance on fire and brilliance. However, research proved that computer-based results could not be the only determining factor in judging a diamond’s overall brightness. After surveying industry leaders and general consumers, GIA created a foundation for the round brilliant cut grade.

When a cut grade is given, it is the component of brightness, fire, scintillation, polish, and symmetry, as well as durability and weight concerns. These are all an integral part that make up the GIA diamond cut grade system. With many different proportion combinations possible, GIA was able to determine the relationship of a stone’s interaction with light.

The reflection of light internally and externally in a diamond is called it’s brilliance. Fire is the dispersion of spectrum colors you see when light hits the diamond. The pattern of light and dark areas and the flash of light that emits when a diamond is moved is called scintillation. A well cut diamond will attribute to these three desired qualities because it directs more light through the top of the stone. A poor cut will appear dark because light is exiting through the bottom of the stone if it is too deep or too shallow.

Diamond cut is often confused with its shape. Round, used in most diamond jewelery, is the shape of a stone. All other shapes are classified under fancy shapes. Evaluated only on polish and symmetry, fancy shapes do not receive a cut grade like the round brilliant. These grades are valued ranging from Excellent to Poor.

Capture2-300x185 Diamonds — GIA's Diamond Shape: Round Brilliant and Fancy Shapes

Polish is rated on the overall surface condition of a diamond’s facets. It is the result of the polishing process and blemishes created after cutting. These grades are given to a diamond when viewed under 10X magnification. An Excellent or Very Good may have minute or minor features that can only be seen with the aid of a microscope. Anything Good or lower can affect the appearance of a diamond and may be seen by the naked eye.

Capture41-300x108 Diamonds — GIA's Diamond Cut Grade: Example of Poor Polish

Symmetry is the exactness of shape and placement of the facets. It is subdivided into two types of features, proportion-related and facet-related. These grades are also performed under 10X magnification for its initial face-up impression and profile view. Both angles are evaluated because of the three dimensional nature of a diamond; one symmetry feature can be linked to others. Similar to polish, grades given Good or lower can have symmetry features that are noticeable to the unaided eye.

Capture3 Diamonds — GIA's Diamond Cut Grade: Example of Poor Symmetry

Understanding GIA parameters for each grade and the specific guidelines they represent, Knox Jewelers recommends fancy shapes to be Good or Better. With almost 30 years of industry experience, we have found that the beauty of a diamond is greatly reduced when selecting polish or symmetry below this standard. A diamond that contains Good or Better qualities enhances the elegance of a handmade Knox custom design.

The care and craftsmanship that goes into each ring is harmonious to the quality of diamond a customer chooses. As the focal point, a diamond captivates the attention with its radiance of sparkle and luster. Selecting a well cut stone to compliment a Knox diamond engagement ring is a timeless expression of love, forever evoking a sense of glamor and romance.

Tag: Scintillation

What is a Round Brilliant Cut?

How Diamond Cut Grade Affects Fire, Sparkle, Scintillation