Last updated on June 13, 2021
People usually evaluate diamonds based on how much they sparkle. Although choosing a stone this way is still legit, the sparkle is not just one thing. Diamond fire, brilliance and scintillation are the three components that make a stone shine brightly with flashes of light.
What Is Diamond Fire, Brilliance and Scintillation?
Diamond fire, also known as dispersion, is the coloured sparkle that you can see when the stone is exposed to light. It is caused by the light that is broken down into spectral hues when it enters a diamond. Diamonds with small tables and steep crown angles, such as old cut stones, produce more fire because this combination also produces less light return. In other words, less light return makes it easier to see colourful flashes that might otherwise be outshined by bright white sparkles (brilliance).
Diamond brilliance is the white light emitted from the stone, which is the foundation of a diamond’s beauty. Brilliance has two main components – brightness and contrast. Bright diamonds perfectly return light to an observer. Diamonds with deep or shallow cut have less brightness because the entering light leaks out of a stone. However, to be brilliant a diamond needs more than just brightness. It should have a good amount of light contrast. For example, a sheet of white paper appears less lively than a chessboard, although it has only half of the light return of a white paper.
Diamond scintillation refers to the blinking flashes of light from facet to facet towards the centre of a diamond when you move the stone. An ideal diamond has many blinking flashes that spread across the surface of the stone. For example, a chessboard looks more “fiery” than a sheet of white paper when moved.
How Diamond Cut Affects Fire, Brilliance and Scintillation
A diamond’s cut quality can make or break its fire, brilliance and scintillation.
Facets make up the surface of diamonds. When light enters the facets, it bounces around, like it would do if hit a series of mirrors, where the light bounces will be determined by the proper cut of the gemstone.
If a diamond is cut in ideal proportions, the stone will bend and reflect light in such a way that fire, brilliance and scintillation will be maximized. On the contrary, the further away from the ideal cut proportions, the less fire, brilliance and scintillation the diamond will show. For example, if a diamond is cut too deep or too shallow, the light will leak out of the bottom of the stone and not return to the observer. As a result, the diamond will appear dull and less lively.
When a diamond is mined, professional diamond cutters evaluate the rough to determine the best cut/shape to maximize its size and natural properties. Whatever the cut, a triple-X stone (stands for triple excellent, meaning excellent cut, excellent symmetry and excellent polish) is the best choice. However, if you want to save some money and get a good amount of fire, brilliance and scintillation, you may go for Very Good or Good cuts but do not settle for Fair and Poor grades.
Can Light Affect Diamond Fire, Brilliance and Scintillation?
Have you ever noticed that in jewellery stores, the lights are arranged and combined in such a way that diamond’s fire, brilliance and scintillation are all enhanced? That is because the type of light a diamond is exposed to is another important factor that affects how much fire, brilliance and scintillation you will see in the stone.
Not all forms of lighting are equal. Different types have varying concentration, which affects specific diamond features. A good combination of light sources maximizes the beauty of a diamond.
For example, a direct beam of incandescent light on a diamond draws out its fire because the beam suppresses white light in the stone. The gemstone darkens, drawing attention to coloured sparkle, while diffused or scattered fluorescent lighting brings out diamond brilliance, due to the light entering the diamond from multiple directions.
Always keep in mind that lights in the store make the diamond you are looking at seem more brilliant and fiery than it would be in daylight. That is why it is very important to see the diamond in natural light before buying.
How Clarity Affects Diamond Fire, Brilliance and Scintillation
Clarity has a great impact on a diamond’s fire, brilliance and scintillation. While clarity is a part of a diamond’s physical properties, fire, brilliance and scintillation are optical effects that can be blocked by inclusions.
The bigger and more numerous inclusions a stone has, the more likely they are to stop light from moving inside and bouncing around properly. A diamond that is heavily included will always look dull even if it has an ideal cut quality.
While diamond fire, brilliance and scintillation are mostly used as indicators of the diamond’s cut quality, they are also an indicator of its clarity.