Meaning

adjective consisting of or containing or of the nature of crystals

adjective distinctly or sharply outlined; - John Buchan

adjective transmitting light; able to be seen through with clarity

originFrom Middle English cristallyn, cristallyne, from Old French cristallin and its etymon Latin crystallinus, from Ancient Greek κρυστάλλινος (krustállinos), from κρύσταλλος (krústallos, “crystal”) + -ῐνος (-ĭnos, adjectival suffix). By surface analysis, crystal + -ine.

Etymology from Wiktionary, CC BY-SA 3.0