Refraction
re·frac·tion | ri-ˈfrak-shən
noun
The act of changing the direction of a light wave so the light enters the object in one direction and leaves it in another
Refraction is the process that occurs when light changes direction after entering an object. Refracted light in the context of a diamond refers to the light that reflects from the facets or girdle of a diamond. Refraction is a useful tool in evaluating and identifying potential exclusions and flaws in the diamond when being evaluated. Refraction helps separate dirt and dust for true inclusions and ensures a better evaluation of the diamond. Refraction is also an important element in the way in which a diamond sparkles. The cut of the diamond, natural state of the diamond, and overall quality will determine its brilliance in this way.