What characterizes labradorescence?

Labradorescence is a distinct optical phenomenon primarily associated with labradorite, a variety of feldspar. The correct characterization of labradorescence involves a broad flash of color that appears to shift as the gem is moved or rotated. This effect results from the interplay of light within the layered structure of the mineral, which creates vibrant colors that can include blues, greens, and golds, among others. This striking visual characteristic is what makes labradorite particularly prized among collectors and jewelers.

While other options cover general attributes of gemstones, they do not accurately represent labradorescence. For instance, a uniform color throughout a gemstone lacks the dynamic play of colors that is essential to the definition of labradorescence. Similarly, the fading of colors with exposure to light speaks to a different optical behavior, which does not describe the phenomenon of labradorescence. Inclusions, while they may affect the clarity and appearance of a stone, do not define the unique color-changing quality of labradorescence. Thus, the broad flash of color that vanishes upon movement is the hallmark that best encapsulates this captivating optical effect.