crys·tal·line 
(krĭstə-lĭn, -līn′, -lēn′)
(krĭstə-lĭn, -līn′, -lēn′)adj.
1. Being, relating to, or composed of crystal or crystals.
2. Resembling crystal, as in transparency or distinctness of structure or outline. See Synonyms at clear.
[Middle English cristallin, from Old French, from Latin crystallinus, from Greek krustallinos, from krustallos, ice, crystal; see kreus- in the Appendix of Indo-European roots.]
crys′tal·lini·ty (-lĭnĭ-tē) n.