1590s, "convert into crystal;" 1660s "form into crystals;" from crystal + -ize. Intransitive sense of "be converted into crystals" is from 1640s. Figurative use, of opinions, love, etc., that are at first indeterminate, "assume a definite form and fixity," is from 1660s. Related: Crystallized; crystallizing.
"process by which molecules of a substance in liquid or vapor form unite and become solid, 1660s, noun of action from crystallize. Figurative use is attested by 1842.
c. 1600, "made into crystal;" 1660s, "formed into crystals," past-participle adjective from crystallize. Of fruit, etc., "preserved by sugar (and usually coated with sugar crystals), by 1875.
It forms all or part of: crouton; crust; Crustacea; crustacean; cryo-; cryogenic; crystal; crystalline; crystallize; custard; encrust; Kristallnacht.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit krud- "make hard, thicken;" Avestan xruzdra- "hard;" Greek krystallos "ice, crystal," kryos "icy cold, frost;" Latin crusta "rind, crust, shell, bark;" Lettish kruwesis "frozen mud;" Old High German hrosa "ice, crust;" Old English hruse "earth;" Old Norse hroðr "scurf."