Diamond Brilliance

A diamond’s sparkle is a combination of three things. These are the fire, scintillation, and diamond brilliance. Scintillation is the flashes between light and dark when a diamond moves in the light. On the other hand, a diamond’s fire is the colored flashes given off by the diamond when in the light.
Then there is the diamond brilliance. This refers to

the brightness of a diamond and how well it can reflect light.
Understanding diamond brilliance
After mining the diamond rough from the earth, it does not display brilliance but has an opaque translucent skin. Only after the diamond is cut and polished does it take on a shiny and brilliant appearance.
To understand diamond brilliance, think of a diamond like a mirror. How a glass absorbs light depends on how straight it is. The straighter the glass the more light it can let through. On the other hand, a warped window surface that is not clear will not let in as much light.
The same concept applies when talking about diamond brilliance. The clearer the diamond is, the more light it can let in and more light it can reflect. Moreover, the angle of the facets also has a lot to do with the diamond brilliance. When the facets are at an optimum angle for light reflection, the light will bounce inside the diamond several times causing the stone to shine.
Cut, polish and diamond brilliance
Cut and polish are two of the most important factors affecting diamond brilliance. The rough diamond is opaque before cutting and polishing. Consequently, it doesn’t let through much light and doesn’t reflect light at all.
The diamond cutter finds the best diamond shape that will make the most of the rough stone. Moreover, he or she decides whether to cut a step cut with fewer facets or a brilliant cut with more facets.
If the cutter chooses a brilliant cut, they cut the diamond rough at specific angles to maximize light reflection. They then polish it to let in as much light as possible into the diamond. The result is more diamond brilliance.
Diamond scintillation and brilliance
Scintillation also affects diamond brilliance. For scintillation to happen, either the diamond or the light source needs to be in motion. A diamond with good brilliance needs to have balanced scintillation. This means some facets should be dark while others have light.