Scintillation

Scintillation refers to the flashes of light or the sparkle seen as a diamond or gemstone is moved under a light source.

Part of speech: noun
Definition: In the jewelry industry, scintillation is a critical characteristic that describes the sparkle or the play of light visible when a diamond or other gemstone is moved under a light. This effect is caused by the reflections of light inside the stone, which are influenced by how well the stone is cut. A well-cut diamond, for example, will exhibit a high degree of scintillation, with numerous small flashes of light seen as the stone moves, enhancing its beauty and appeal. Scintillation is one of the key factors considered in evaluating a gemstone's quality, alongside color, clarity, and carat weight, making it a major determinant of the stone's allure and value.