nacreous in WordNet English dictionary

1. having a play of lustrous rainbow colors
   "an iridescent oil slick"; "nacreous (or pearlescent) clouds looking like mother-of-pearl"; "a milky opalescent (or opaline) luster"
   iridescent  nacreous  opalescent  opaline  pearlescent 
   
2. consisting of or resembling mother-of-pearl
   nacreous