An Etymological Dictionary of Astronomy and Astrophysics

A property of some crystalline materials (e.g. calcite, quartz) which have different indices of refraction associated with different crystallographic directions. Therefore, the crystal splits incident transmitted light into two beams, each polarized perpendicularly to the other. Also called double refraction.

Etymology (EN): Birefringence, from → bi- + refringence, from L. refringere “to break up,” from → re- “back” + combination form of frangere “to break.”

Etymology (PE): Došekast, from do- “two,” → bi- + šekast “breaking,” from šekastan “to break up,” Mid.Pers. škastan, Av. skand- “to break.”