noun
also iceland crystal
Usage: usually capitalized I
: a transparent calcite the best of which is obtained in Iceland, which easily cleaves into rhombohedrons, and which is used for polariscope prisms because of its strong double refraction
noun
also iceland crystal
Usage: usually capitalized I
: a transparent calcite the best of which is obtained in Iceland, which easily cleaves into rhombohedrons, and which is used for polariscope prisms because of its strong double refraction
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012