A translucent material that appears blue in reflected light and red-orange in transmitted light is described by which term?

A translucent material that appears blue in reflected light and red-orange in transmitted light is described by which term?

• A. Opalescence
• B. Metamerism
• C. Fluorescence
• D. Gamma phase

Answer: (A)

Opalescence describes how a translucent material can look blue when light is reflected from its surface but red-orange when light passes through it. This happens because microstructures within the material scatter shorter wavelengths of light more effectively in the reflected view, giving a blue appearance. The transmitted light, after passing through the material, loses much of that blue due to scattering, so the longer wavelengths dominate and appear red-orange. This scattering-based color behavior is different from fluorescence (emission after excitation) and metamerism (color matching under different light sources). The term opalescence captures the observed blue-in-reflection, red-orange-in-transmission effect.

Opalescence describes how a translucent material can look blue when light is reflected from its surface but red-orange when light passes through it. This happens because microstructures within the material scatter shorter wavelengths of light more effectively in the reflected view, giving a blue appearance. The transmitted light, after passing through the material, loses much of that blue due to scattering, so the longer wavelengths dominate and appear red-orange. This scattering-based color behavior is different from fluorescence (emission after excitation) and metamerism (color matching under different light sources). The term opalescence captures the observed blue-in-reflection, red-orange-in-transmission effect.