The Collaborative International Dictionary
Hydrophane \Hy"dro*phane\, n. [Hydro-, 1 + Gr. ? to show, appear: cf. F. hydrophane.] (Min.) A semitranslucent variety of opal that becomes translucent or transparent on immersion in water.
Wiktionary
n. (context mineral English) A semitranslucent variety of opal that becomes translucent or transparent on immersion in water.
Usage examples of "hydrophane".
Bardel acknowledged the applause, hung the great hydrophane amulet around his own sweaty neck, pledged packtrains of Lyrian wine as gifts for Moess and Shandor.
Dirrach to reassure himself that the fresh windfall of mana was genuine and resided, not in outlander sorcery, but in hydrophane opals.
If the locus of power lay in hydrophanes, then none but Dirrach himself could be allowed to have them during the coming power struggle.