We investigated the homogeneous nucleation and subsequent evolution of polymers of sickle cell hemoglobin (HbS) using differential interference contrast (DIC) microscopy. The same technique was employed to determine the liquid liquid separation boundaries for a variety of conditions in solution of sickle cell and normal human hemoglobin. The HbS polymers were also imaged using atomic force microscopy. We found that the location of Liquid-Liquid phase boundary under conditions that mimic those in the erythrocytes is consistent with previous determinations of the spinodal for this phase transition. Increasing the ionic strength shifts this phase boundary to significantly lower temperatures and fib concentrations. We also found that the nucleation of individual HbS fibers indicates that the process is random and follows statistics similar to those established for nucleation of crystals or liquid droplets from vapors.