iridize

Century Dictionary and Cyclopedia

1. To make iridescent, purposely or by the action of slow decay. See iridescent glass, under iridescent.
2. To cover with iridium; tip with iridium.

Wiktionary

1. v. transitive To point or tip with iridium.
2. v. transitive To make iridescent.

GNU Webster's 1913

1. v. To point or tip with iridium, as a gold pen.
2. v. To make iridescent.