Diamond scintillation is the term used to describe the visible flashes of light that occur when the diamond moves. This is also known as brilliance, or the sparkle you see in your diamond. Scintillation effects will be often be greatest in brightly lit environments and is an extremely positive attribute of a diamond. Scintillation is effected by the size and amount of diamond facets, symmetry (must be symmetrical to maximize light reflection), and polish (a well polished diamond encourages better light reflection.