opalescence

The quality of being opalescent; iridescence like that of the opal; a play of colors milky rather than brilliant; the property of exhibiting such a play of color.

A reflection of a milky or pearly light from the interior of a mineral, as in the moonstone; the state or quality of being opalescent.

the state of being opalescent

the milky iridescent appearance of a dense transparent medium when it is illuminated by polychromatic visible radiation (such as sunlight) due to local fluctuations in its density and therefore in its refractive index

the visual property of something having a milky brightness and a play of colors from the surface