Diamond Glossary  Scintillation: 1. Sparkle: The appearance, or extent, of spots of light seen in a polished diamond when it is viewed face-up that flash as the diamond, observer, or light source moves.
2. Pattern: The relative size, arrangement, and contrast of bright and dark areas that result from the internal and external reflections seen in a polished diamond when it is viewed face-up while that diamond is still or moving.