Learn how to say Crystallised correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word crystallize:
to form or cause to form crystals; assume or cause to assume a crystalline form or structure
to coat or become coated with sugar ⇒ crystallized fruit
to give a definite form or expression to (an idea, argument, etc) or (of an idea, argument, etc) to assume a recognizable or definite form