the effect or quality of being iridescent; iridescence
Word origin
[1850–55; iris + -ation]This word is first recorded in the period 1850–55. Other words that entered Englishat around the same time include: ethos, ethylene, headhunting, overprint, proletariat-ation is used to form nouns from stems ending in -ate (separation) and, on this model, to form nouns from stems of other origin (starvation). Other words that use the affix -ation include: complementation, neutralization, plantation, sensitization, transportation