irisation

[ ahy-ri-sey-shuh n ]
/ ˌaɪ rɪˈseɪ ʃən /

noun

the effect or quality of being iridescent; iridescence.

Origin of irisation

First recorded in 1850–55; iris + -ation
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019