opalescence vs iridescence

opalescence and iridescence both are nouns.

Word	Noun	Adjective	Verb	Adverb
opalescence	Yes	No	No	No
iridescence	Yes	No	No	No

As nouns, opalescence and iridescence are synonyms defined as:

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

opalescence (noun)	iridescence (noun)
the visual property of something having a milky brightness and a play of colors from the surface	the visual property of something having a milky brightness and a play of colors from the surface