How does a window typically differ from the rest of the stone?

The concept of a "window" in a gemstone refers to an area where light passes through, usually from a lack of sufficient material to create full color and depth that is present elsewhere in the stone. This difference is primarily observed in saturation and intensity of color. In a window, the color is often less vibrant and more pale compared to the saturated hues found in the rest of the gemstone. Such discrepancies in saturation arise from variations in the thickness of the material as well as any inclusions or other factors that may affect light performance.

When assessing gemstones, it's essential to recognize that the areas lacking saturation—such as windows—can dramatically alter the visual appeal and value of the stone. A highly saturated gemstone is typically more desirable, as it presents a richer and more dynamic visual experience than areas that might appear washed out. Therefore, saturation accurately encapsulates the characteristic distinguishing windows from the rest of the stone.