Found 2 items, similar to Iceland spar.
English → English (WordNet) Definition: Iceland spar Iceland spar n : a transparent calcite found in Iceland and used in polarizing microscopes
English → English (gcide) Definition: Iceland spar Iceland spar \Ice"land spar`\ (Min.) A transparent variety of calcite, the best of which is obtained in Iceland. It is used for the prisms of the polariscope, because of its strong double refraction. Cf. Calcite. [1913 Webster]