Unsolved Problems in Crystal Growth: Challenges for the Future

In the last six decades revolutionary changes have occurred in the field of crystal growth.  The mechanisms by which crystals grow at low supersaturations (spiral growth from screw dislocations), and high supersaturations (2 dimensional nucleation of various types) are understood.  Surface characterization techniques have improved to molecular resolution.  However, progress has been unexpectedly slow on several fronts, including models that are capable of predicting absolute growth rates (not just relative growth rates of crystal faces), the precise effects of solution environment at the solvent-surface interface on growth, and most perplexing of all, the mechanisms by which polar crystals grow.  In this presentation I will focus on solution effects, which seem within reach, and on polar crystals, which do not.