Opalescent
op·al·es·cent | ˌō-pə-ˈle-sᵊnt
adjective
A term used to describe a surface with a lustrous, cloudy, rainbow-like array of colors, similar to what one might see in an oil slick or mother of pearl
Opals are known for their iridescent appearance, showing a range of colors that give them a play of color similar to that of fire. The colors themselves vary widely, so the term opalescent has been used to describe any surface that has a lustrous, rainbow-like array of colors, often cloudy, and sometimes unclear. This term is often used for non-gemstone-related objects or circumstances that refract a wide array of light, such as oil slicks, or mother of pearl which can have a similar effect. There are several different types of opals and the term can be used to describe different circumstances as a result - including the fire-like effect of fire opal and the milky colorfulness of precious opal.