This invention relates to a novel system for making uniform crystals. The system, by virtue of the nature of its crystal product, is useful in various chemical, pharmaceutical, agricultural, and biotechnology applications. The invention features physically separated and controlled crystal nucleation and growth zones useful in industrially scaled crystallization processes. The invention also provides a method to preferentially nucleate and crystallize a desired category of crystal structure (enantiomer, solvate, polymorph) of non-chiral and chiral compounds.