hydrophane

hy·dro·phane

H0348100 (hī′drə-fān′)n. An opal that is almost opaque when dry but transparent when wet.
hy·droph′a·nous (hī-drŏf′ə-nəs) adj.

hydrophane

(ˈhaɪdrəʊˌfeɪn) n (Minerals) a white partially opaque variety of opal that becomes translucent in water hydrophanous adj

hy•dro•phane

(ˈhaɪ drəˌfeɪn)

n. a partly translucent variety of opal that becomes more translucent or transparent when immersed in water. [1775–85] hy•droph•a•nous (haɪˈdrɒf ə nəs) adj.